# Arrow Penetration Tests update



## sharpbroadhead (Feb 19, 2004)

I posted the following penetration tests a few months ago and had some guys telling me that bone would have been better - so I did a quick update on bone with broadheads:

Arrow Penetration Part 1 of 2:

http://www.youtube.com/watch?v=t4RGcyZ_gJY

Arrow Penetration Part 2 of 2:

http://www.youtube.com/watch?v=VAfK0sBsZBw

And the update on bone:

http://www.youtube.com/watch?v=_vKslydefg0&feature=related


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## Kurt Blanken (Apr 12, 2011)

KE versus inertia *here we go...*


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## Ft. Jefferson (Apr 11, 2011)

Give me light every time. I like fast arrows for targets and hunting. Have found just like this man that light and fasts penetrates better on game. For some reason the traditional crowd is way behind the compound crowd in this respect.


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## BLACK WOLF (Aug 26, 2005)

The third video...I'm not sure what it proves....other than that both arrows can penetrate through a piece of bone placed on a target. Most anyone with enough bowhunting experience could of guessed the outcome of that test based on the equipment being used.

The average whitetail bowhunter doesn't need alot of KE or MO to kill a deer let alone penetrate a bone set up like that test was with typical trad bowhunting gear.

The issue becomes important on larger game animals as in African dangerous game that require more energy from the arrow to pass through the tougher hide, through the tissue, through the bone and into the lungs.

At what point is there a major difference when going with a lighter or heavier arrow out of the same bow...I don't know...but my choice in a situation where I'm hunting Cape Buffalo is...I'm going to go with the heavier slower arrow rather than the lighter faster arrow...within reason of course.

My biggest concern with penetration regarding arrows...is not weight as long as the arrow weight is within reason...but how tuned my arrows are to my bow.

My current bowhunting set-up is about 8g./lbs. and I primarily hunt elk. If I was to hunt Dangerous Game I would definitely increase that ratio.

Ray :shade:


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## LBR (Jan 1, 2004)

I haven't watched the videos yet, but I will sooner or later. As mentioned, it doesn't take much to penetrate small, thin-skinned game. If you want to know what penetrates big critters, ask people like Rick McGowan, Ed Ashby, or most any guide for dangerous game. 

Asiatic Water Buffalo is my "Dream Hunt". I've talked to hunters and guides for hours. Everyone I've talked with, at least those who have experience, say the same thing--heavy arrows, not light. I know what I'll be using when I go.

Chad


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## sharpbroadhead (Feb 19, 2004)

I would not increase that ratio unless I could demonstrate that it penetrated deeper into some consistent medium - I suspect it would not - but if you can demonstrate that it does - I would like to see the video or at least how you did the test so I could test it at home myself. If a lighter faster arrow penetrates deeper than a slower heavier arrow into a phonebook and ballistic gel - why would it be any different in an animal? There may be a point where there is a perfect balance between weight and velocity with any given set up - but I suspect that it wouldn't make a hill of beans of difference in the real world. I agree 100% that a tuned set up is very important and would add that accuracy is king.


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## LBR (Jan 1, 2004)

> If a lighter faster arrow penetrates deeper than a slower heavier arrow into a phonebook and ballistic gel - why would it be any different in an animal?


Danged if I know--I just know what the guys that have shot big critters, and seen them shot (with light and heavy arrows) have told me.

The target medium could well be the difference. With the buffalo for instance: what you have to penetrate is generally a layer of mud (dried usually), hair, heavy hide (inch thick or more), heavy muscle, most likely a rib, then into the vital cavity and pierce the heart. It's not a nice, neat, tight package like gel or a phone book.



> I agree 100% that a tuned set up is very important and would add that accuracy is king.


Same here--wobbly arrows rob penetration, and a pass-through ain't worth squat if it's in the gut.

Chad


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## benofthehood (May 18, 2011)

LBR, when you get here mate , the 'buff will be waiting ... with that stare that they get ... it ain't pretty !!! But up close it sure is a bunch of fun.
But , as I'm sure you will do , having listened to people who have actually been there and done it , don't be turning up with light arrows ... or the guides will leave you at camp . They have better things to do than chase wounded game , particularly game that weighs over a ton and scoffs at .338 Win mags .
For deer and other thin skinned game , penetration is not that much of an issue regardless of arrow weight [ as long as the arrow is flying well and broadhead sharp] as "sharpbroadhead" has alluded to ad infinitem all over cyber space ... but against large , thick skinned dangerous game I'll listen to the advice of the fella's who have been there and done it like the Mcgowans, Hintons, Thomas and Tiezel's ... 


and as 'broadhead correctly says ... "accuracy is king " ..... 
Thanks for posting more video's Sharbroadhead ... they are always well made and informative . Its good to see guys standing behind there opinions :thumbs_up


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## Whitey375 (Mar 26, 2009)

I know it isn't the same scenario, but I have been doing a series of broadhead/penetration tests over in the Western forum. The first two were apples to apples comparisons as far as broadheads go, just at 20 and 40 yards, strictly testing the difference in penetration with different arrow weights. The other two are just different heads, same arrow weight.
I think there becomes a point of diminishing returns in regards to arrow weight, in relationship to arrow speed. I know speed doesn't do all the killing, it is an integral part.


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## sharpbroadhead (Feb 19, 2004)

Chad - good point about the fur - I wonder if there is a way to replicate it and test. The thing that I wonder about regarding the fact that everyone who has hunted large dangerous game with heavy arrows - is that - has anyone tried anything else? I have no doubt whatsoever that a heavy arrow is deadly - my penetration tests demonstrated that the difference in penetration between a light and heavy arrow is really minimal and that both will get the job done.

I guess I think of a story that Paul Harvey once told on the air: A young woman was visiting with a friend while preparing a roast and as she was preparing it she cut the ends of the roast before putting it in the pan. Her friend asked her why she did this. She replied that she wasn't sure, but that her mom always did - so she does too. Well the next day she decided to ask her mom why she cut the ends off the roast. Her mom told her that she did it cause her mom did. So now this young woman is really curious - so she calls her grandmother and asks her. Her grandmother says that she did it because her mom always did. Now she is beside herself with curiosity - so she drives to the nursing home and visits her great-grandmother and asks her why she always cut the ends of the roast off before putting it in the pan. Her great- grandmother replied by saying: "Oh - that is because my pan was to small for the roasts from the local butcher"!


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## sharkbone (Dec 5, 2010)

Has anyone seen this test?

http://www.youtube.com/watch?v=lgdM91K_uuw&feature=related


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## BLACK WOLF (Aug 26, 2005)

sharkbone said:


> Has anyone seen this test?
> 
> http://www.youtube.com/watch?v=lgdM91K_uuw&feature=related


Just did. Yep....broadhead choice definitely plays a huge roll in an arrow's penetrating potential.

Ray :shade:


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## sharpbroadhead (Feb 19, 2004)

that is why I did not want to use a broadhead to test - that involves a whole new set of variables - and in reality - there are soooo many possible combinations of arrow weight and broadhead design, etc... - that the possibilities are almost endless.

there is a new device out that Sean Callanan is testing that might answer some of these questions - it is called a Velocitip - and it is a screw-in field point that is actually a sophisticated sensor that measures kinetic energy, momentum and velocity at all points in the flight of the arrow and at impact. 

Sean tells me that he is compiling some very interesting data and some of it is surprising. It will be interesting to see what the conclusions are after this testing.


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## Kurt Blanken (Apr 12, 2011)

There are an incredible number of factors that determine penetration. It is up to every archer to find the optimal weight for their setup.

If weight were the most important everyone would shoot solid steel arrows, but that doesn't happen.


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## WindWalker (Jan 23, 2005)

Other tests:

*LINK:* http://www.youtube.com/watch?v=NZ1Mg0a7Tpw&NR=1

*LINK:* http://www.youtube.com/watch?v=WfpzDYogmnM&NR=1

*LINK:* http://www.youtube.com/watch?v=WLHO6TsxaPI&NR=1


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## Whitey375 (Mar 26, 2009)

WindWalker said:


> Other tests:
> 
> *LINK:* http://www.youtube.com/watch?v=NZ1Mg0a7Tpw&NR=1
> 
> ...


Those are good videos. I had seen the last two, but the first one I had not. I like the main guy in the first, seems like quite a character.


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## LBR (Jan 1, 2004)

> ...has anyone tried anything else?


Yes--with compound bows...absolute horror stories.

Chad


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## Ft. Jefferson (Apr 11, 2011)

The first several whitetail deer I ever shot years ago were shot with an 85# longbow and wooden arrows of about 580 grains. I cant remember the exact weight but they were well over 500. I used sharp 2-blade broadheads (Ace) and never achieved a complete pass through on a broadside hit. I only shoot at broadside animals. No head on or going away angles. In every case the arrow punching 90% of the way through but did not poke out the other side. (usually) This was still more than enough to kill.

When carbon arrows came along I tried them and loved the flight and flat trajectory. Using longbows of similar weight all my next whitetails were shot with carbon arrows with 2-blade broadheads weighing around 450 grains and moving quite a bit faster than the heavy wood. In every case when I hit a deer (unless I caught the shoulder bones) the arrow whipped through and stuck in the ground beyond the deer. Two wound holes to bleed from.

I've even achieved similar results shooting our wild pigs down here in Florida. I never shot through a hog untill I switched to light carbon arrows. As for African game, I feel shooting really large dangerous game with a traditional bow is more a stunt than anything else. I would not do it and would rather use a large bore rifle of good energy. I really don't like the practice of seeing IF I can kill something for some kind of thrill.


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## LBR (Jan 1, 2004)

> The first several whitetail deer I ever shot years ago were shot with an 85# longbow and wooden arrows of about 580 grains.


Either you were shooting at bionic deer, or you had something wrong somewhere. It only takes slightly more energy to shoot through a whitetail than it takes to shoot through a paper sack (shoulders not included). I have no problem burying my wood arrows in the ground behind the deer with 2 or 3 blades, and I only pull 66#. My best friend's daughter has killed a couple pulling less than 30#--on a recurve.



> I really don't like the practice of seeing IF I can kill something for some kind of thrill.


Can't blame you there, especially if you had that much trouble with deer. However, many people have proven over and over that with properly tuned equipment, the right broadhead, and heavy arrows, the bow and arrow can take down large game as quickly and cleanly as a rifle--moreso in some cases. Do your part, there is no more "IF" with a buffalo than with a whitetail, bow or rifle.

Chad


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## sharpbroadhead (Feb 19, 2004)

WindWalker

In the first of those three videos - only one arrow is shot into the hog - there is no comparission of another heavy arrow shot out of the same bow in the same spot - How do we know if a heavier arrow shot out of the same bow in the same spot with the same broadhead would not have done the same thing?

In the 2nd video he is using two bows and shooting both the heavy arrow and the light arrow at virtually the same speed - well - of course the heavy arrow will penetrate more if it is moving at the same speed as a light arrow - if you wanted to truly compare light vs heavy - he should have used the same bow - because then the heavy arow is travely MUCH slower.

In the 3rd video he is using different designed broadheads on each arrow - and in that video the only difference in penetration resulted because the heaviest of the 3, by his own admission did not catch as much of the shield - and he even admits - pretty much what my test showed - that there is not much difference at all in penetration between different weight arrows out of the same bow.

When he did it out of the other bow - they both passed through - we don't really know where the first one hit because it went completely through

What he did show is obvious - out of a heavier draw bow a heavier arrow will penetrate deeper than a lighter arrow out of a lighter draw bow.

I am also curius - if the gpp of draw is an issue - I mean - most would not shoot a 400 grain arrow out of a 70lb recurve - that would be less than 6 gpp.

It could drive you crazy all the variables.

I know this - out of my bow and the way I shoot - my testing showed no significant difference in penetration - as I showed in my video - with a different bow and different style of shooting - results may be different.

I think everyone should do some testing with their set up and find what works best for them.


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## STUDENT-ARCHER (Jun 26, 2009)

I like seeing test data, but shoulder blades vary GREATLY in density depending where you hit, not to mention the ridge... I am a firm believer that testing in ballistics gel is a level playing field and gives us the data we are seeking, consistant apple to apple comparison. Now, if we're looking to compare broadhead cutting abilities, a layer of thick carpet over the ballistics gel would provide some additional info...and be an even test from arrow to arrow.


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## whitewolf1 (Jun 28, 2006)

sharpbroadhead said:


> that is why I did not want to use a broadhead to test - that involves a whole new set of variables - and in reality - there are soooo many possible combinations of arrow weight and broadhead design, etc... - that the possibilities are almost endless.
> 
> there is a new device out that Sean Callanan is testing that might answer some of these questions - it is called a Velocitip - and it is a screw-in field point that is actually a sophisticated sensor that measures kinetic energy, momentum and velocity at all points in the flight of the arrow and at impact.
> 
> Sean tells me that he is compiling some very interesting data and some of it is surprising. It will be interesting to see what the conclusions are after this testing.


I have to question why anyone(not just you) would setup a penetration test and NOT use broadheads? The purpose of a penetration test in my mind is to gauge terminal performance of a hunting setup. Who gives a flip which arrow penetrates best on a bale, block or 3d target, you dont get extra points for sinking your arrow deeper in a target.

Dr. Ashby's studies have been done on game animals with about every kind of arrow setup and broadhead combination imaginable and they have proven that a heavy arrow combined with a 2 blade head of a 3:1 ratio perform the best. That is on big, tough african game. 

Before reading his studies, I got suckered into the whole light and fast argument and set up some light weight carbons that were paired with thunderheads that I shot from my compound. I went from 100% passthru's to about 60% passthru's. I went back to heavy arrows and havent had any issues since except for when using 1.75" cut expandables and the passthru rate is about 70%. Never tried a light hunting setup with my trad bows and wont. Heavy and sharp works for me so that is what I am going to stick with.


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## sharpbroadhead (Feb 19, 2004)

whitewold - I wanted to test one variable at a time - that is why I did not test with broadheads. I tried to remove as many variables as possible - ie: shooting arrows that were all tuned to the bow, shooting arrows that were all the same diameter, same tip design, etc... I know what I did was not perfect - but it satisified me and I just wanted to share what I found.

If you do any testing with broadheads - film it and post it I would be interested to see what you come up with.


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## whitewolf1 (Jun 28, 2006)

sharpbroadhead said:


> whitewold - I wanted to test one variable at a time - that is why I did not test with broadheads. I tried to remove as many variables as possible - ie: shooting arrows that were all tuned to the bow, shooting arrows that were all the same diameter, same tip design, etc... I know what I did was not perfect - but it satisified me and I just wanted to share what I found.
> 
> If you do any testing with broadheads - film it and post it I would be interested to see what you come up with.


Didnt intend to come across as knocking your test. I have seen several vids where similar test were done and broadheads were not used. If we hunted with field tips that might make sense but we dont. I understand and agree with your line of thought in keeping variables as close as possible but that can be done by using the same broadhead on each arrow and adjusting weight in other ways.

If it satisfies you, nothing else matters imo. Each of us have to find the setup for our rig that gives the performance we are looking for and more importantly imo, performance that we have absolute confidence in.


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## Ft. Jefferson (Apr 11, 2011)

LBR: I don't believe for one minute much of the shoot data coming out of Africa from writers who go there largely promoting such and such a product. Video cannot be trusted because you can easily edit out bad hits or failed shots that don't put game down. All we ever see are the successful shots by the famous man humping product X.

No doubt you can kill anything with a bow. I just thing killing really large, heavy-boned game in Africa with any bow is a stunt - not a really sporting thing to do. I still have the image of my guy Howard Hill repeatedly shooting a chained elephant for the camera in "Tembo". Not only is the elephant not dieing in an artistically fashionable manner, but he's actually struggling mightly with one foot anchored and all kinds of hollering going on as Hill repeatedly shoots him at fairly close range. Not a pretty picture if you ask me. Hill has many shots of him repeatedly shooting large animals only to see them suffer for a good long time before finally keeling over.

Today that stuff would be edited out. But I feel it's far more representitive of the truth. While I have never shot anything larger than a heavy hog (250#) on land, I have shot many large sharks off my boat with a bow and have never been impressed with either penetration or killing ability on those big fish, some over 600 pounds I figured.

I remain unconvinced shooting water buffalo or elephants with a bow is anything but a silly stunt by men who should know better but need the attention it garners through their videos and written articles for archery magazines.


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## Sanford (Jan 26, 2009)

ft. Jefferson said:


> i remain unconvinced shooting water buffalo or elephants with a bow is anything but a silly stunt by men who should know better but need the attention it garners through their videos and written articles for archery magazines.


amen!!!


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## IAIS604 (Apr 11, 2010)

sanford said:


> amen!!!


x2 !!!


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## Whitey375 (Mar 26, 2009)

sharpbroadhead said:


> .
> 
> If you do any testing with broadheads - film it and post it I would be interested to see what you come up with.


I took pictures, if that counts. I just don't have a video camera that would work.


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## WindWalker (Jan 23, 2005)

sharpbroadhead:

Videos were not posted as a challenge to your tests. Just some "real life" information and comments from those who have experienced light vs. heavy on live game.

As for me, I have no stories of personal experience with results of what is considered light arrows vs. heavy arrows on large or small game. I have always used arrows that are considered to be in the "heavy" category on all game and with consistently good results. The lightest setup I know I have used is somewhere around 490 grains and the heaviest at about 611 grains.

I use what is considered heavy shafts not just for the penetrative value, but also for noise control, reduced bow shock, and flight stability. I also believe that my using heavy shafts is why I have never had a bow fail and why I am still able to use a couple of 'curves that are 41 and 39 years old.

This argument of the penetration value of light arrow vs. heavy arrows has been raging for years but has never caused me to consider experimenting. From real life experience on game; _"I knows what I knows if ya knows what I mean.."_


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## sharpbroadhead (Feb 19, 2004)

post the pics - we can all learn from this stuff


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## Eldermike (Mar 24, 2009)

mass times velocity squared (Ke) is useless information when considering cutting tools (this is used as a marketing thing since the advent to compound bows where velocity is king) while mass times velocity (p momentum) is useful.
If I take a made up example using the same bow and three arrows as show below, I come up with:
300 grain arrow @ 200 fps = p (momentum) 8.4 lb/ft/sec
500 grain arrow @ 160 fps = p 11.36 lb/ft/sec
250 grain arrow @ 210 fps = p 6.3 lb/ft/sec

There may well be results from actual tests that show something other than what should be a no brainer. I hunt with heavy arrows.


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## Ft. Jefferson (Apr 11, 2011)

Windwalker, I tend to think the issue on a whole is much ado about nothing. In Fred Bear's day most hunters used wooden shafts with glue-in heads of 125-150 grains and killed just about everything on earth except elephants with arrows that rarely exceeded 600 grains and most were much lighter. My average 11/32 wooden arrow of 28 inches and with a 145 field point or broadhead only weigh about 515 grains depending on shaft weight of course. My favorite raw shaft range is 380-400 grains. This yields my average 515 when made up as described above. 

Guys shot arrow like this all the time in years gone by and never knew they were "under weight".


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## Ft. Jefferson (Apr 11, 2011)

Eldermike said:


> mass times velocity squared (Ke) is useless information when considering cutting tools (this is used as a marketing thing since the advent to compound bows where velocity is king) while mass times velocity (p momentum) is useful.
> If I take a made up example using the same bow and three arrows as show below, I come up with:
> 300 grain arrow @ 200 fps = p (momentum) 8.4 lb/ft/sec
> 500 grain arrow @ 160 fps = p 11.36 lb/ft/sec
> ...


Your madeup examples are all wrong. The differences in speed would be much greater over such a wide range of weights. Real example: My 75# Martin Hunter recurve shot 375 grain carbons at 227fps. Same bow shooting 500 grain 2117 alloy arrows was about 185 fps. Still fast but nowhere near the lighter carbon arrow. 

Your post kinda confuses me because I've always found those light, fast carbon arrows to penetrate anything much more than the slower, heavier arrow. Speed is not to be disregarded. I feel it's the single most imortant element assuming good arrow flight.

I've always felt tradtional shooters have felt inferior to compound shooters and look for ways to justify their slow arrows. So instead of admitting faster is better, they do the only thing they can do and promote heavy, slow arrows. We do heavy and slow because we can't match compound fast and light. We use our slow bows pushing heavy arrows as a sales point. It's basic sales promo stuff: take a negative and turn it into an asset. A phony asset, but a asset all the same.

Luckily heavy slow arrows seem to kill just fine. We've been killing stuff for years with them. But my own eyes show me light and fast is much better for accuracy at extended range and for the holy grail of the traditional archer - penetration. Fast and light carbons drive in like crazy.


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## LBR (Jan 1, 2004)

> LBR: I don't believe for one minute much of the shoot data coming out of Africa from writers who go there largely promoting such and such a product.


Neither do I. None of the data I've gathered was from anyone promoting a product, or from a video. I got my information from people who guide, hunt, and/or kill Asiatic and/or Cape Buffalo with archery equipment. Like Ben said--show up in camp with light arrows, the guides will leave your butt sitting there. These guides' livelihood is based on bringing their clients home safely, not selling a broadhead or a bow or an arrow brand.



> I still have the image of my guy Howard Hill repeatedly shooting a chained elephant for the camera in "Tembo".


That was a movie, not a hunt. It's like saying Bambi is a hunting video. Try watching Fred Bear's "Mozambique Game Trails", but you really need the book "Fred Bear's Field Notes: The Adventures of Fred Bear" to go along with it. You get the real "behind the scenes" story from the book. One arrow, one dead elephant, from a real hunt.



> I remain unconvinced shooting water buffalo or elephants with a bow is anything but a silly stunt by men who should know better but need the attention it garners through their videos and written articles for archery magazines.


What do you base that on? How many of these hunters have you actually spoken with? How much do you know about these types of hunts? 

There are lots of hunters that you'll never hear about doing these hunts. I talked to one last week who's name I never heard of. He hunts for himself, not anyone else. As far as I know he's never filmed a video for the public or written an article for a magazine.

Then you have the guys that will share thier hunts via video or article. I'm thankful for them, otherwise I'd never have a clue that it's possible for me to live out my dream hunt. I have no plans of video or writing an article, but I'm sure I'll post about it once I've done it. Lots of folks, like myself, love to read these stories. Folks like Denny Sturgis Jr. make the required sacrifices (it takes a lot of time, money, preparation, practice, etc.) to travel to foreign countries and risk their lives for the ultimate hunting experience. I don't know, but I'd bet he's spent a lot more money hunting than the articles and video of his hunts will ever bring in.

'Course most people don't have the cajones for such a hunt--some will just sit back and ridicule (from a distance) those who do have the guts to take on the challenge. I guess they get some sort of weird satisfaction from making fun of people with talents and courage they could never hope to posess? *I dunno...but it sure seems that way.*

Everyone has their own opinions. Some folks feel that shooting long distance targets is making up for shortcomings in other departments, some don't like the idea of hunting something that can hunt you back. Some feel a need to question authority to draw attention to themselves. For my part, I feel that it takes a whole lot more courage to risk life and limb on a hunt than to risk loosing or breaking an arrow or risk loosing posting priveledges for a few days, but that's just my opinion. 

Back to the topic...

In less than a month I'll be visiting with Mr. Denny Sturgis Jr.--you know, one of those glory hounds that's so desparate for attention (notice he's always posting here, talking about all his accomplishments with bow and arrow). He's one of many I've talked with about hunting big critters (he has a ton of experience shooting things that weigh well over 150#--and getting great penetration on them). I plan to bend his ear while admiring his trophies and see what works best for him. 

As it stands, it seems the folks that have actually been there/done that share a concensus--heavy works on big game, light doesn't. 

Chad


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## Whitey375 (Mar 26, 2009)

sharpbroadhead said:


> post the pics - we can all learn from this stuff


My penetration/broadhead tests are posted in the Western bowhunting forum. The first two pertain to the discussion here. The other two are durabilty tests.


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## Ft. Jefferson (Apr 11, 2011)

Good post, Chad. But I remain unconvinced and do not appreciate your intimation I lack guts for not hunting elephants and buffalo. I happen to be a bluewater sailor who has faced far more actual deadly moments hundreds of miles offshore and out of touch of the Coast Guard than any white hunter shooting darts at big, dumb animals for fun.
I've even survived a pitch-poled 45' sailboat in the Indian Ocean that killed a woman on board and left us without a mast and electronics and with the deck torn loose from the hull for 3 days until Indian authourities picked us up. It was much more dangerous than a bow hunt with a double rifle behind the camera. You're way out of line this time.


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## LBR (Jan 1, 2004)

> But I remain unconvinced and do not appreciate your intimation I lack guts for not hunting elephants and buffalo.


If real-life experience from people who guide for a living doesn't convince you, then you simple don't want to believe the facts. 

I made a general statement based on my observations, no more and no less. I didn't say everyone, and I sure didn't say "Ft. Jefferson". My implication was toward whoever it fits, period.



> I happen to be a bluewater sailor *who has faced far more actual deadly moments* hundreds of miles offshore and out of touch of the Coast Guard *than any white hunter shooting darts at big, dumb animals for fun*.


Again I ask, what do you base this on? Obviously not your own experience. Have you ever studied it? Talked with guides and/or hunters? Studied the habits and anatomy of these animals? Read about any real hunts? If not, then you really don't know what you are talking about, correct?

I'll let you in on a story. I believe it was Monty Browning's guide that told him that, when you are in bow range of a Cape or Asiatic Water Buffalo, your life is in your own hands. Reason being is when you are that close, there is no hunting rifle made--not even the big-bore double rifles--that can stop one of the buffalo before it can kill you. I've heard of it taking as many as 13 rounds from a double-rifle to put one down, after someone screwed up and used arrows that were too light to get the job done.

Anyhow, you risk your life to get your jollies one way, but ridicule someone else doing the same thing? And, according to you at least, your way is much more dangerous? And I'm the one who's out of line? Okey-dokey then.

I will make a correction--I should have said "some" will just sit back and ridicule. I'll fix that part.

Now, let's see if we can get this back to penetration. I really enjoy these threads--might learn something new.

Chad


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## Sanford (Jan 26, 2009)

LBR said:


> I've heard of it taking as many as 13 rounds from a double-rifle to put one down, after someone screwed up and used arrows that were too light to get the job done.
> 
> Chad


There's an arrow heavy enough to "drop" a Cape??? It can take 13 rounds from a rifle to do it, but one heavy arrow can? If your close, and even a rifle kill is too slow a put down, how does the heavy arrow work into that reasoning?


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## LBR (Jan 1, 2004)

If I thought you had a genuine interest, I'd do my best to pass on the information I've gathered, the difference in trauma/shock vs. hemmorage, energy used for penetration vs. expending it in the target, etc. 

However, since you think it's only folks seeking attention that participate in such hunts to begin with (post #26 on this thread), I believe you are just trying to derail the topic (again) with nothing to add, and I have no desire to participate in such.

Back to penetration.

Chad


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## sharpbroadhead (Feb 19, 2004)

Windwalker - I did not take it that those videos were a challenge to mine - I just pointed out some reasons why they did not really accurately compare a light to heavy arrow. I think that those videos demonstrated quite well that if you make a bad hit on a hog - you want a heavy draw weight bow if you hope to recover one.


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## Sanford (Jan 26, 2009)

LBR said:


> If I thought you had a genuine interest, I'd do my best to pass on the information I've gathered, the difference in trauma/shock vs. hemmorage, energy used for penetration vs. expending it in the target, etc.
> 
> However, since you think it's only folks seeking attention that participate in such hunts to begin with (post #26 on this thread), I believe you are just trying to derail the topic (again) with nothing to add, and I have no desire to participate in such.
> 
> ...


Actually, I know where they all hang on the wall, some of the big 5 game mounts - including Cape. I know the bows that were used and the arrows, along with the knowing the shooter very well and knowing the folks who own the lodge and guide the shoots. For the bows used, the arrows would be considered light - this shooter prefers light arrows - light by the standard of his bow. "Heavy" is relative to the bow and not the arrow. That's relevant and non-derailing.


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## Eldermike (Mar 24, 2009)

Ft. Jefferson said:


> Your madeup examples are all wrong. The differences in speed would be much greater over such a wide range of weights. Real example: My 75# Martin Hunter recurve shot 375 grain carbons at 227fps. Same bow shooting 500 grain 2117 alloy arrows was about 185 fps. Still fast but nowhere near the lighter carbon arrow.
> 
> Your post kinda confuses me because I've always found those light, fast carbon arrows to penetrate anything much more than the slower, heavier arrow. Speed is not to be disregarded. I feel it's the single most imortant element assuming good arrow flight.
> 
> ...


Those examples are not far off my lastest results with 50lb TT limbs. 160fps to about 200pfs with those weight differences. I do agree there are other factors in penetration such as broadhead choice and dia of the shaft, length and such as those things. However I wanted to point out that KE is not a factor in killing it's a marketing thing. But momentun is a factor in penetration. Again my examples are close to reality but they only consider one factor in the equation of penetration.


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## Eldermike (Mar 24, 2009)

I own a 458 WIN MAG, pre-64 super grade, beautiful functional thing it is; I'll take it hunting dangerous game....my bows are for animals that run off once shot. If an arrow goes all the way through a dangerous animal he/she still has to bleed out before the end of the event I started with my arrow from 20/30 feet away. Penetration will not solve that problem.


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## Ft. Jefferson (Apr 11, 2011)

Mike, I only expected to see a much larger speed gap with arrows having a 200 grain weight difference. In my experience timing shots such light arrows (300gr) almost go supersonic. LOL


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## Eldermike (Mar 24, 2009)

Ft. Jefferson said:


> Mike, I only expected to see a much larger speed gap with arrows having a 200 grain weight difference. In my experience timing shots such light arrows (300gr) almost go supersonic. LOL


I wish


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## LBR (Jan 1, 2004)

> Penetration will not solve that problem.


Nobody said it would. There's a lot more to hunting dangerous game than just making the shot. However, the topic is about penetration (one little part of the whole), not all the details of hunting dangerous game.

Chad


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## benofthehood (May 18, 2011)

This whole debate seems to be re invented with bizarre regularity . For med to large sized game , I don't know of anyone who would debate that almost any well flying arrow will do the job. I am wondering though, how many here have actually been up close to thick skinned big game , let alone hunted it .
The derision of other hunters whom choose to do so , whilst these men and woman pay good money to participate in what are mostly well managed conservation projects that pump invaluable assets back into such programs , is intriguing . 

Mind you , people and guides I know such as Mick Baker , Pat Macnamara...hunters such as Rick Mcgowan , Rik Hinton and Doug Chase must have been hoodwinked by the heavy arrow crowd ...:embara:
Dr Ashby is a good bloke who shares his time and findings with anyone who is willing to listen . He is the first person to be open to different findings and suggestions . To suggest that there are ulterior motives .. again ? Why don't you ring him up or send him an email ... 

Punching paper , foam and 200lb deer is very very different to 1500lb game . 
Some people have experienced it in real life , some people live and work with such animals in some of the most hostile environments on earth. To discount their opinions with no first hand knowledge of such is just ignorant.

And i hunt with 9gns per pound outta my bows ..... plain ol' Magnus double bevel heads .....


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## BLACK WOLF (Aug 26, 2005)

benofthehood said:


> This whole debate seems to be re invented with bizarre regularity . For med to large sized game , I don't know of anyone who would debate that almost any well flying arrow will do the job. I am wondering though, how many here have actually been up close to thick skinned big game , let alone hunted it .
> The derision of other hunters whom choose to do so , whilst these men and woman pay good money to participate in what are mostly well managed conservation projects that pump invaluable assets back into such programs , is intriguing .
> 
> Mind you , people and guides I know such as Mick Baker , Pat Macnamara...hunters such as Rick Mcgowan , Rik Hinton and Doug Chase must have been hoodwinked by the heavy arrow crowd ...:embara:
> ...


:thumbs_up

Ray :shade:


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## LBR (Jan 1, 2004)

> Rik Hinton and Doug Chase must have been hoodwinked by the heavy arrow crowd ...
> Dr Ashby is a good bloke who shares his time and findings with anyone who is willing to listen . He is the first person to be open to different findings and suggestions . To suggest that there are ulterior motives .. again ? Why don't you ring him up or send him an email ...
> 
> Punching paper , foam and 200lb deer is very very different to 1500lb game .
> Some people have experienced it in real life , some people live and work with such animals in some of the most hostile environments on earth. To discount their opinions with no first hand knowledge of such is just ignorant.



Spot-on Ben. I've asked twice if F.J. has any actual experience, done the least bit of homework on the topic, even read up on it--no reply. The answer is obvious, I just wanted to know if the questions would be answered. Guess not.

Not sure what to expect on a message board anymore. People choosing mythical "right people" for advice over proven coaches and champions. Bionic deer that can't be penetrated with 80+ lb bows and heavy arrows. And ignoring the combined experiences of dangerous game hunters in favor of?????


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## sharpbroadhead (Feb 19, 2004)

My question is this - if a heavier arrow has more penetrating ability than a lighter arrow - how come in both the phonebook and the ballistic gel in my test were the results the opposite? Why would the heavier arrow suddenly be able to penetrate more on dangerous african game than it did on a phonebook and ballistic gel?

this is a serious quesiton - not meant to start a huge debate - just an honest question.


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## BLACK WOLF (Aug 26, 2005)

sharpbroadhead said:


> My question is this - if a heavier arrow has more penetrating ability than a lighter arrow - how come in both the phonebook and the ballistic gel in my test were the results the opposite? Why would the heavier arrow suddenly be able to penetrate more on dangerous african game than it did on a phonebook and ballistic gel?
> 
> this is a serious quesiton - not meant to start a huge debate - just an honest question.


I think that's a fair question and one definitely worth researching more.

I know you paper tuned...but I'm not a big fan of that unless I have first seen and tested all shafts with the bareshaft tuning method....because I am such a big believer in energy robbing effects of an out of tuned arrow....even if the arrow flight is still acceptable to some people with the feathers on them.

If you don't mind could you post the specifics of those arrows. It will just make it easier to reference.

Arrow weight?
Tip weight?
Arrow speed?
Arrow diameter?
Tip diameter?
etc. etc.

Thanks!

Ray :shade:


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## benofthehood (May 18, 2011)

Ken, I think it is a fair point you bring up ... I would assume Jack Howard asked the same question after his own testing way back when ! 

I am not sure of the reasoning and am always open to different idea's. In the meantime , the next time I'm up against a Buff I'll tackle the heavy arrow ... :shade:


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## WindWalker (Jan 23, 2005)

> _My question is this - if a heavier arrow has more penetrating ability than a lighter arrow - how come in both the phonebook and the ballistic gel in my test were the results the opposite? Why would the heavier arrow suddenly be able to penetrate more on dangerous African game than it did on a phonebook and ballistic gel?
> _


It's likely a result of the mediums being used and the answer lies somewhere within the studies of the coefficients of friction. Certain types of opposing friction affect weight and mass differently than what one might expect.


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## sharpbroadhead (Feb 19, 2004)

Here is my arrow information

Carbon Tech Cheetah 400 (without weight tube)
349 grains 214 fps 32 1/2 inches long 100 grains saunders tip

Carbon Tech Cheetah 400 (with weight tube)
539 grains 178 fps - 32 3/8 inches long - 145 grain saunders tip

Gold Tip Traditional 5575
562 grains 174 fps 32 7/8" long with a 175 grain tip and nock adapter

The arrows all used the same inserts and are the same inside diameter - the Gold tips are slightly larger in diameter because of the "traditional" woodgrain finish that is applied. The reason for the slightly different lengths and the different tip weights and the nock adapter were to get them all to fly well out of the same bow. That was the most difficult part of this test - getting three different weight arrows to be reasonably comparable in everything except weight and still all be tuned out of the same bow. It took hours and hours to accomplish this.

Bow information:
Tradtech Pinnacle with Extreme BF Limbs
Angel Majesty 18 strand string and Majesty serving
47lbs @ my draw of 29 3/4 inches


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## Kurt Blanken (Apr 12, 2011)

WindWalker said:


> It's likely a result of the mediums being used and the answer lies somewhere within the studies of the coefficients of friction. Certain types of opposing friction affect weight and mass differently than what one might expect.


Although this is true for fluids, I am not sure how it applies to solids. In a fluid medium the resistance is proportional to the speed of the penetrating object, and therefore the object with the highest inertia with regards to momentum will lose the least amount of energy.

This does not apply to solids. Energy (in the form of KE) is required to move the solid out of the way of the projectile (cutting). More than that I cannot say.


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## Ft. Jefferson (Apr 11, 2011)

WindWalker said:


> It's likely a result of the mediums being used and the answer lies somewhere within the studies of the coefficients of friction. Certain types of opposing friction affect weight and mass differently than what one might expect.


No, the truth is fast and light penetrates better. But tradition says heavy is better long before really light arrows came around. Most people tend to stick with what they have believed since birth it would seem. Again, not phone books or Jello - all my deer since switching to light carbon of about 455 grains have been complete pass throughs rattling off into the brush. I never got performance like that shooting heavier arrows. My carbons are going about 210, the old heavier arrows about 170-180. I use the same broadhead style - non-vented 2-blade like Eclipse, Zwickey etc. The lighter, faster arrows penetrate noticably better and are much easier to be accurate with beyond 20 yards. What's not to love?


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## benofthehood (May 18, 2011)

> Your heroes are not young, stupid boys like I was. Your guys are mostly inadequate fools trying to prove something to themselves. Or they are self-promoting jackasses doing no good for the promotion of normal archery. I know they wound and injure lots of game that gets finished off with the gun.


They are also people who pour a lot of money into well managed conservation programs which ensure that the animals and the wild places they live are here for years to come . To infer that these people are "mostly inadequate fools" or "self promoting jackasses" is perhaps just a tad harsh .:embara:

I don't know of wounding rates but do know the guys that guide them on Buff hunts here in Oz . I asssume that you are getting this information from a trustworthy source . 


The internet archery world is getting wierder and wierder by the day ... 

Now back to heavy vs light ....... arrows that is , not beer ........:teeth::teeth::teeth:


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## tiny52 (Dec 31, 2010)

Ft. Jefferson said:


> No, the truth is fast and light penetrates better. But tradition says heavy is better long before really light arrows came around. Most people tend to stick with what they have believed since birth it would seem. Again, not phone books or Jello - all my deer since switching to light carbon of about 455 grains have been complete pass throughs rattling off into the brush. I never got performance like that shooting heavier arrows. My carbons are going about 210, the old heavier arrows about 170-180. I use the same broadhead style - non-vented 2-blade like Eclipse, Zwickey etc. The lighter, faster arrows penetrate noticably better and are much easier to be accurate with beyond 20 yards. What's not to love?


:set1_signs009:


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## tiny52 (Dec 31, 2010)

sharkbone said:


> Has anyone seen this test?
> 
> http://www.youtube.com/watch?v=lgdM91K_uuw&feature=related


boring and worthless.
The shots were not together and therefore do not have the same mass encountered.
Shots that are not placed in the same area are worthless as to usable data.

We used beef shoulders that were from the local slaughter house.
Our test shoulders were from animals that shared the same relative weight and body mass.
All scapula's were shot on the high ridge...one shot per shoulder,

Multiple shots into any bone will skew the outcome due to fracturing throughout the area from the previous shot.

Keep that in mind.


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## sharpbroadhead (Feb 19, 2004)

good point tiny - btw - what did your testing show


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## benofthehood (May 18, 2011)

Ft. Jefferson said:


> No, the truth is fast and light penetrates better....."
> 
> Gee, Thanks for sorting that out for us .
> 
> ...


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## Widgeon (Jul 17, 2009)

I think a little needs to be said about test methodology because on almost all of the threads that I have read about penetration, this is the one thing that is almost universally ignored or messed up. When you do any kind of testing, you have to control all of the variables as tightly as possible. In the case of arrow penetration testing, the points need to be IDENTICAL, being similar to each other is not going to cut it. Arrow outside diameter and finish needs to be IDENTICAL, once again, close is not going to cut it. FOC and proper tuning of the arrows are also extremely important as well. If you do testing and thing that things are "close enough" all you end up with is anecdotal information that isn't necessarily valid. 

Proper testing is hard. It is not easy and requires a lot of thought, preparation and actual testing. It also takes many data points, not just one or two. A large portion of my daily job as a mechanical engineer revolves around taking my (and other's) designs and properly testing them to get valid results. If I screw up, the company loses money and people in the real world can be harmed or even die. I do not take testing lightly! I have made mistakes and learned from them and I am sure I will make more mistakes in the future so I am certainly not saying everything I say or do is perfect and I do not want to discredit or discourage any of the testing that shows up here or elsewhere on the web. However, I will strongly state that unless you do proper, controlled testing, the results are possible useful, perhaps close to truth and often bogus.

All that being said, I have started some initial testing in order to learn more about penetration and about how to better test it. You can see some of my initial findings here: http://archeryreport.com/2011/03/arrow-penetration-testing-real-bows-real-arrows-real-results/ This first batch of shooting was mostly to gain a better understanding of how I can perform more testing in the future. There is a lot more to come and now that youth spring soccer is ending I'll have more time to get back to it.

My initial results and all of the physics that I know and study tell me that in a mostly fluid like media, heavier is always going win. When hard impacts are concerned, the impulse of the impact becomes a bigger factor and speed will provide some advantage for the initial, brittle impact but beyond that heavier should win out. I'll be setting up some solid impact testing shortly and will share more results when I have them.


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## benofthehood (May 18, 2011)

[


> *Anything is possible if you don't know what you are talking about*


That is the best signature i have seen in a while ...

I look foward to your findings .


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## LBR (Jan 1, 2004)

> My initial results and all of the physics that I know and study tell me that in a mostly fluid like media, heavier is always going win.


You mean those bowfishing gear manufacturers know what they are doing???? Ludicrous!

I love the sig too!

Chad


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## sharpbroadhead (Feb 19, 2004)

I agree Widegon - that is why in my testing I did my best to limit the variables as much as humanly possible while still having arrows that all had virtually the same FOC, outside diameter, and tune and also why I tested in both a dry solid medium - the phonebook and in a semimoist/solid medium - ballistic gel. There is no possible way that you will get rid of all the variables and still have arrows that are tuned to the bow that have different weights, but we can get rid of most of them. I thought it would be easy - till I started bareshafting and paper testing the different weight arrows - it took a lot of time and messing around to get them to fly perfect and still be varied in weight.


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## LBR (Jan 1, 2004)

I can understand the head-scratching over test results, but in real-world "testing" heavy wins. Bowfishing or big game. Want to see a light, fast arrow stop quicker than a slow, heavy one? Shoot it into water. Shoot a bullet into water even--no arrow can begin to approach that speed, but water stops it. Mammals are made up of mostly water.

That's about as technical as I'll get on this one.

Chad


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## sharpbroadhead (Feb 19, 2004)

yea - water stops bullets too - but animals don't - bullet proof vests top bullets, but not arrows - all this stuff can make you go crazy. All I know i that when I decided to try a lighter arrow - everyone told me that I was crazy and would have penetration problems - to date I have not had any issues with penetration and my accuracy has improved considerably - going from an average of 242 to 268 in my winter league 3D. But I still worried because all the trad guys kept telling me I was asking for trouble - so that is when I started testing and then made a video of my results. I am certainly not saying that my tests are the end all by any stretch - but they convinced me that my set up is fine for what I do. If I wanted to hunt dangerous game in Africa - I would probably shoot a heavier draw bow than 47 lbs.


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## benofthehood (May 18, 2011)

sharpbroadhead;106090262 I am certainly not saying that my tests are the end all by any stretch - but they convinced me that my set up is fine for what I do.[/QUOTE said:


> The many photo's of your whitetails and IBO stuff attests to that ...:thumbs_up


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## WindWalker (Jan 23, 2005)

> _No, the truth is fast and light penetrates better. But tradition says heavy is better long before really light arrows came around. Most people tend to stick with what they have believed since birth it would seem. Again, not phone books or Jello - all my deer since switching to light carbon of about 455 grains have been complete pass throughs rattling off into the brush. I never got performance like that shooting heavier arrows. My carbons are going about 210, the old heavier arrows about 170-180. I use the same broadhead style - non-vented 2-blade like Eclipse, Zwickey etc. The lighter, faster arrows penetrate noticeably better and are much easier to be accurate with beyond 20 yards. What's not to love?
> _


You say that the truth is that a fast and light arrow penetrates better.....because you now have pass-throughs when with heavier arrows you apparently did not. Your results are not thoroughly scientific nor the last word. Your personal experience does not mean that everyone would experience the same results nor does your personal experience prove that a light arrow penetrates better than a heavy arrow. 

I also do not consider 455 grains of shaft to be a "light" shaft. It may be on the lower end of the most common range of weight that trad shooters tend to shoot; but not "light."

Because small diameter carbon shafts are stiffer than wood or aluminum of a comparable diameter and carbon does not flex as much as wood or aluminum and do not oscillate as much as wood or aluminum upon impact, carbons utilize the stored energy more efficiently and retain more of the downrange momentum. That alone will tend to enhance penetration. 

As for... _"Most people tend to stick with what they have believed since birth it would seem,"_ that statement tends to imply that you believe you can't teach old dog's new tricks and, therefore, those that may be sticking with what they learned at birth are behind times. If so; you foolish man. Most of the longtime, hardcore, bowhunters I know/knew have/had proven gear that was bulletproof and highly efficient. We/they don't consider it smart to swap our Goodyear Eagles for ridin' on rubber band-wrapped 24's.

As for a "pass-through" being the gauge for efficiency; I have yet to purchase a set of shafts or heads that came with a written "pass-through" guarantee. With some of my big boy shafts I have literally dropped deer in their tracks, broke a shoulder, and had a shaft ricochet along the rib cage, etc, without obtaining a pass-through, but the deer never traveled far.

I have never used "light" shafts and never will. Based on my experience I have no need to.

"Walk softly and carry bigs sticks."


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## LBR (Jan 1, 2004)

> bullet proof vests top bullets, but not arrows


Good point.


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## Kurt Blanken (Apr 12, 2011)

WindWalker said:


> Because small diameter carbon shafts are stiffer than wood or aluminum of a comparable diameter and carbon does not flex as much as wood or aluminum and do not oscillate as much as wood or aluminum upon impact, *carbons utilize the stored energy more efficiently* and retain more of the downrange momentum. That alone will tend to enhance penetration.


So you agree that higher KE (and therefore speed) is more important than inertia?


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## rattus58 (Jul 9, 2007)

Ft. Jefferson said:


> Give me light every time. I like fast arrows for targets and hunting. Have found just like this man that light and fasts penetrates better on game. For some reason the traditional crowd is way behind the compound crowd in this respect.


Not at all... and KE does not out penetrate momemtum... KE in simple terms delivers the arrow, momentum drives the arrow through the game.


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## Ft. Jefferson (Apr 11, 2011)

With regards to fast and light: I, too, would prefer a fast heavy arrow as compared to a fast light arrow. But given a single bow of fixed draw weight, the only way to increase speed is to lighten the arrow. If you want a faster heavy arrow you need to change bows for something heavier or more efficient.

Few people do this because they are already at the peek of their weight ability. So they lighten their arrows and pick up speed. What they then find is a seemingly out of proportion increase in penetration over their earlier heavier arrow choice. This was my finding and the findings of others who have actually done this and not just read about it.


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## BLACK WOLF (Aug 26, 2005)

At some point...while using the same bow without changing draw weight or brace height....there should be an optimal g./lbs. that is most efficient in regards to maximum penertration out of that bow and arrow combination. I doubt it's going to be 6g./lbs. and I doubt it's going to be 14g./lbs. My guess is that it's somewhere inbetween those numbers.

Ray :shade:


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## emac396 (Jul 7, 2010)

Can't resist have to add my .02 I have thought allot about this over the years speed helps penetration shaft dia and broadhead size affects penetration and obviously arrow weight. I honestly believe there is not a definite answer to what penetrates deeper a slow heavy or lite fast, to many variables every setup is different but I do know it is your responsibility to make sure your set up will humanly kill what ever it is you are shooting at. And if your not sure your not gonna go wrong with heavy. Finding the right combination for you and your setup is fun just means you have to shoot more. And Sharpbroadhead great job on your tests every time I log on this is first thread I go to.


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## IAIS604 (Apr 11, 2010)

KE = P**2/2m

where P = momentum (squared in the formula), and m = mass.

For a given mass (m) of arrow, kinetic energy and momentum are proportionally related (well, exponentially proportional) - hard to really separate the two and say one over the other, IMHO.


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## whitewolf1 (Jun 28, 2006)

sharpbroadhead said:


> yea - water stops bullets too - but animals don't - bullet proof vests top bullets, but not arrows - all this stuff can make you go crazy. All I know i that when I decided to try a lighter arrow - everyone told me that I was crazy and would have penetration problems - to date I have not had any issues with penetration and my accuracy has improved considerably - going from an average of 242 to 268 in my winter league 3D. But I still worried because all the trad guys kept telling me I was asking for trouble - so that is when I started testing and then made a video of my results. I am certainly not saying that my tests are the end all by any stretch - but they convinced me that my set up is fine for what I do. If I wanted to hunt dangerous game in Africa - I would probably shoot a heavier draw bow than 47 lbs.


Ken, I think one of the issues not being discussed here but that imo is an important factor to consider is that your light arrow was roughly 7.5 grns per pound of draw and the heaviest arrow was 12. Every bow has a finite amount of energy that is stored and then released. The arrow will not except 100% of that energy. The combination of arrow weight that will except the maximum amount of stored energy from the bow should give the higest penetration. In other words, for your bow "IF" say 9.5 grns per pound is the arrow weight that would except all of the transferable energy from your bow, it should out penetrate the 7.5 grn arrow and the 12 grn arrow. The 7.5 grn arrow would not be accepting all of the available energy and with the 12 grn arrow the bow is having to push unneccesary weight from a maximum performance standpoint.

Every bow is going to be slightly different and some are going to be substantially different based on each bows energy storage capacity and efficency. Light and heavy will always be a relative discussion atleast until someone comes up with a formula that most closely ties energy storage, transfer efficiency and arrow weight with penetration outcomes. If that is done, then the only other substantial discussion point that I can think of becomes the working properties of the broadhead which would serve to enhance the penetration capability of the arrow and Dr. Ashby has pretty thoroughly covered that aspect.


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## sharpbroadhead (Feb 19, 2004)

I suspect that you are right about some perfect weight for a given bow - but I think the difference would be negligable. I am not a fan of Dr. Ashby and certainly do not subscribe to his single bevel is best theory, but to each their own.


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## Widgeon (Jul 17, 2009)

Kurt Blanken said:


> So you agree that higher KE (and therefore speed) is more important than inertia?


Just remember that higher arrow weight equals more kinetic energy. The increased arrow weight may slow down the arrow somewhat, but the gains in bow efficiency (in both traditional and compound bows) outweigh the speed gain and KE goes up, as well as momentum.

Anyone who touts that KE or momentum are the best indicators of an arrow's penetration capability also tout that heavier arrows are better (though many don't seem to understand this!)


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## Widgeon (Jul 17, 2009)

whitewolf1 said:


> Ken, I think one of the issues not being discussed here but that imo is an important factor to consider is that your light arrow was roughly 7.5 grns per pound of draw and the heaviest arrow was 12. Every bow has a finite amount of energy that is stored and then released. The arrow will not except 100% of that energy. The combination of arrow weight that will except the maximum amount of stored energy from the bow should give the higest penetration. In other words, for your bow "IF" say 9.5 grns per pound is the arrow weight that would except all of the transferable energy from your bow, it should out penetrate the 7.5 grn arrow and the 12 grn arrow. The 7.5 grn arrow would not be accepting all of the available energy and with the 12 grn arrow the bow is having to push unneccesary weight from a maximum performance standpoint.
> 
> Every bow is going to be slightly different and some are going to be substantially different based on each bows energy storage capacity and efficency. Light and heavy will always be a relative discussion atleast until someone comes up with a formula that most closely ties energy storage, transfer efficiency and arrow weight with penetration outcomes. If that is done, then the only other substantial discussion point that I can think of becomes the working properties of the broadhead which would serve to enhance the penetration capability of the arrow and Dr. Ashby has pretty thoroughly covered that aspect.


I have yet to find a compound bow that does not increase KE and momentum when shooting heavier arrows, up to almost 1500 grains. I have not tested as extensively on light weight compounds (under 50 lbs) or stick bows, but what testing I have done on them shows this trend of heavier equals more KE holds true as well.


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## IAIS604 (Apr 11, 2010)

KE = 1/2 m v**2

So if the velocity can be kept the same, KE will increase with increasing mass (as does momentum of course, as they are related).
Note that increasing the velocity would have a greater impact on the KE than increasing the mass (v is a squared term).

As momentum P = mv, increasing either would directly increase the momentum IF the other term can be held constant.


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## whitewolf1 (Jun 28, 2006)

sharpbroadhead said:


> I suspect that you are right about some perfect weight for a given bow - but I think the difference would be negligable. I am not a fan of Dr. Ashby and certainly do not subscribe to his single bevel is best theory, but to each their own.


I would not expect a significant difference if you split a 5 grn per pound weight difference either. But consider this, if in that example above that maybe the 9.5 grn arrow would out penetrate the 7.5 and the 12 grn arrows, in the argument of light vs heavy, who is right? 

I put a lot of value in Dr. Ashby's studies but I think one has to interpret that information relative to what type of game they are chasing. For whitetails, I feel very confident shooting snuffers or woodsmans because the target isnt all that tough and I know from experience that they will more than get the job done and I like a 3 blade head. Big hogs on the other hand I would stick to a well built 2 blade. In all cases, they would be on an arrow in the 9-10 grn per pound of draw because from my experience that combination works. Your experience may dictate something entirely different. If that is the case, I'd say we are both right for what we each are hunting and what we are hunting it with.


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## Widgeon (Jul 17, 2009)

IAIS604 said:


> KE = 1/2 m v**2
> 
> So if the velocity can be kept the same, KE will increase with increasing mass (as does momentum of course, as they are related).
> Note that increasing the velocity would have a greater impact on the KE than increasing the mass (v is a squared term).
> ...


Do not neglect the fact that bow efficiency increases with arrow weight. Just because you see a formula with a squared component does not immediately tell you the dominant variable unless you fully understand how all the variables relate to each other.


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## fnds (Dec 2, 2010)

Widgeon said:


> Do not neglect the fact that bow efficiency increases with arrow weight. Just because you see a formula with a squared component does not immediately tell you the dominant variable unless you fully understand how all the variables relate to each other.


Can we say that arrow speed decreases as arrow weight increases for a given bow and draw length? The rate of speed loss probably decreases for heavier arrows because energy transfer is better.

The consensus of the guys that have "been there and done that" is go heavier, but maybe there is not a "right" answer and for any given bow it is necessary to test many combinations of arrow weight and speed and compare with the penetration for each combination. Has anyone ever done this kind of test? It's not a linear relation and the exact "sweet spot" will be different from bow to bow. So it's "possible" that some bows will have better penetration with a faster arrow and other bows will have better penetration with a heavier arrow. It all depends on how the bow reacts to changes in arrow weight. 

Is it possible that the "sweet spot" of speed/weight will vary for different target distances? Maybe that should be taken into consideration as well, since speed starts to drop the moment the arrow leaves the string. If possible, arrow speed should be measured right before impact.

Very interesting thread. Thanks.

--fnds


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## Sanford (Jan 26, 2009)

fnds said:


> If possible, arrow speed should be measured right before impact.
> 
> Very interesting thread. Thanks.
> 
> --fnds


That would be prudent, but the media plays a role as well. Ex: Foam targets melt and grab with frictional heat. Diameter of shaft (frictional surface) plays into this as well as speed (frictional/heat). Many, many variables at play.


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## IAIS604 (Apr 11, 2010)

Widgeon said:


> Do not neglect the fact that bow efficiency increases with arrow weight. Just because you see a formula with a squared component does not immediately tell you the dominant variable unless you fully understand how all the variables relate to each other.


Well, we can easily see how KE (and thus P), mass and velocity relate - what other variables do we have?

The arrow has mass, is given KE/P by the bow, and a stabilizing spin by the feathers/vanes. 

And, of course, has the sharp blades, which do the trick. (For a large animal, say a deer, we are not killing by blunt force impact. That would be a factor in a small animal) 

I don't understand your term "bow efficiency" (sorry, sounds like a marketing term), nor how it would relate to the arrow weight.
If you mean that a stronger bow will increase the velocity of a heavier arrow over that of a weaker bow, that is still the KE (or the P, if you want that term - they are interchangeable).

Can you explain any other variables ???

The only other thing I can think of is air resistance, and that is a function of arrow design. You would need a stronger bow to shoot a poorly designed arrow to gain back the KE lost in flight, but I don't think we are considering arrow design?


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## Widgeon (Jul 17, 2009)

When a bow is pulled back, potential energy is stored in it and upon release that energy is converted into the kinetic energy of the bow as well as noise, vibration and other parasitic losses. The heavier the arrow, the higher percent of the potential energy is converted to kinetic energy in the form of arrow speed. In other words the efficiency increases.

When looking at the KE formula, seeing that velocity is squared does not mean that the mass is less important. There is no linear relationship between how mass and velocity affect the KE because of the change in efficiency of the bow due to changes in arrow weight.


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## IAIS604 (Apr 11, 2010)

Widgeon said:


> When a bow is pulled back, potential energy is stored in it and upon release that energy is converted into the kinetic energy of the bow as well as noise, vibration and other parasitic losses.


True, obvious. 



> The heavier the arrow, the higher percent of the potential energy is converted to kinetic energy in the form of arrow speed. In other words the efficiency increases.


 For the lighter arrow to lose more in the PE transfer, some other energy loss must be occurring (law of conservation of energy). By the experimental data given by the posters above, sometimes this seems to happen, but other times the lighter arrow has more KE (putting their mass and velocity data into the KE formula). I suspect measurement errors, as for a given test set the values are within 8% of each other at most. I'm not saying you are wrong, but above data is inconclusive on this point. All lighter arrows have the greater speed in the tests, as expected.



> When looking at the KE formula, seeing that velocity is squared does not mean that the mass is less important. There is no linear relationship between how mass and velocity affect the KE because of the change in efficiency of the bow due to changes in arrow weight.


Never said mass was unimportant. I DID say the relationship was exponentially proportional between velocity and KE. For a given velocity, KE is directly proportional to the mass.


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## kegan (Aug 28, 2006)

Widgeon is 100% correct on how a bow and arrow work together. The heavier arrow ALWAYS absorbs more energy from the bow, making the bow more efficient. How fast the arrow goes depends on efficiency and stored energy. Flight bow shooters favor efficiency. Broadhead flight shooters favor stored energy. Naturally builders try to build for both.

Light arrows show evidence to the lower absorbed energy by more noise or vibration, especially if the tune is off. A well tuned set up can be fairly quiet, but still more noisey than a heavy arrow. This all comes from the massive experimentation by the many individuals who sought to bring back selfbows, as well as the many more interested in flight shooting. 

As for penetration, I'd rather trust the evidence gathered from not just one source... but the many, many, many archers who've conducted them over the years.


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## IAIS604 (Apr 11, 2010)

Ok, Kegan, I can buy vibration loss.

I would like to see more supporting evidence of how much is lost.

By the above data, it is 4% deviation from the mean on the data that shows the heavier arrow with more KE.

What that translates to in a real hunting situation, I don't know.

But as this is not a physics class (and I am not a physicist), I'll drop it.

"Dam it Jim, I'm a chemist, not a physicist!"


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## Kurt Blanken (Apr 12, 2011)

TERMS AND WHAT THEY MEAN:

*Inertia: *Inertia is the property of any given object to resist a change in momentum. Inertia is directly related to mass as far as we are concerned.

*Momentum: *Momentum is related to velocity and mass. It is not a property but a measurement and has a direction. In a closed system, momentum is conserved. [_Related - _ an elastic collision is when two objects move away from each other, an inelastic collision is when they stick together. Arrow penetration is an inelastic collision, energy is lost during this collision.]

*Kinetic Energy: *Energy is the ability of an object to do work. Work is the transfer of energy, force over distance. Kinetic energy is more reliant upon velocity than mass.

Thus it is more useful to talk about inertia vs. KE than momentum vs. KE. Two arrows with equal momentum can have different mass/velocity distribution. The one with higher velocity/lower mass will have more KE, the other will have more inertia. The one with higher inertia will retain more of its KE between the bow and target because of fluid resistance forces and how they act. Muscle and bone are not fluids and they do not act the same way in regards to inertia or KE of a penetrating object.


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## WindWalker (Jan 23, 2005)

When is the exam?


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## kegan (Aug 28, 2006)

IAIS604 said:


> Ok, Kegan, I can buy vibration loss.
> 
> I would like to see more supporting evidence of how much is lost.
> 
> ...


The closest I could gather, as it quickly became more than my little mind could handle, was that in most instances the difference in efficiency varies from bow to bow depending entirely on design, and the only time it really has any real-life effect is when pushing some sort of limit (flight shooting for example). As far as hunters go... it seemed we don't really need to know any of that. In the end the only time it really comes into play is when trying to use a lighter arrow from a bow that lackes an efficient design. You just get noise and handshock instead of serious speed increase. Like some of the Hill-style bow duplicates out there. Some just won't let you shoot an arrow approaching 6 or 7 gpp without tearing every ligament in your arm apart!

On the topic of the original post, it seems even Ashby's studies supported that there were more factors than weight alone to get penetration, as he was able to get the same penetration with a 64# ACS bow or somehting and 650 gr. EFOC or ultra-EFOC arrow as with an 80-90# straight bow and 800+ grain arrow not so well designed. Seems there never will be any easy answers for us?


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## IAIS604 (Apr 11, 2010)

WindWalker said:


> When is the exam?


Was going to be today, but got postponed for the end of the world.

Rescheduled for Monday .... :wink:


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## rattus58 (Jul 9, 2007)

IAIS604 said:


> KE = P**2/2m
> 
> where P = momentum (squared in the formula), and m = mass.
> 
> For a given mass (m) of arrow, kinetic energy and momentum are proportionally related (well, exponentially proportional) - hard to really separate the two and say one over the other, IMHO.


If you understand the exponentialiality, it is fine, but here is the rub...

grains	400
speed	350
KE	108.7801088
Momentum	0.621600622
momentum_1	6.216006216

grains	450
speed	310
KE	96.003996
Momentum	0.619380619
momentum_1	6.193806194

grains	500
speed	280
KE	87.02408702
Momentum	0.621600622
momentum_1	6.216006216

grains	550
speed	255
KE	79.3956044
Momentum	0.622710623
momentum_1	6.227106227

grains	600
speed	235
KE	73.55977356
Momentum	0.626040626
momentum_1	6.26040626

grains	650
speed	215
KE	66.7027417
Momentum	0.62049062
momentum_1	6.204906205

grains	700
speed	200
KE	62.16006216
Momentum	0.621600622
momentum_1	6.216006216

grains	750
speed	187
KE	58.22344322
Momentum	0.622710623
momentum_1	6.227106227

Notice anything?


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## FORESTGUMP (May 14, 2008)

rattus58 said:


> If you understand the exponentialiality, it is fine, but here is the rub...
> 
> grains	400
> speed	350
> ...



:evil5::nyah:

I notice from all this that sometimes all the formulas and number juggling can as well be stored under the "thats nice/thank you for that information" heading.

And then there's the real world. My own experience has been that lightweights always fail miserably in penetration on animals and a good heavy arrow,within reason of course, will almost knock em off their feet. Sure,flatter trajectory is good but doesn't mean a thing if it's got no balls left upon arrival.

My conclusion: Never shoot wimpy arrows!!!!!!!


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## Widgeon (Jul 17, 2009)

You can't trust online calculators and much of the other software out there to properly predict the effect of bow efficiency. While I don't have good data sets for stick bows (though they do behave the same, I need to do more testing on them before posting results), here are some real world results for you:


























This phenomena is also easily demonstrated by shooting a light arrow then a heavy arrow and noticing the difference in vibration and noise. The heavier arrow will invariably be quieter and more vibration free. As the weight of the arrow increases, more of the initial potential energy will be converted into the speed of the arrow and its associated kinetic energy. There will always be some noise, vibration, friction and other parasitic losses, but with heavier arrows, the efficiency increases. I'm sure at some point the weight of the projectile will be so heavy as to cause a breakdown in function of a bow and the efficiency will start to drop, but up to 1450ish grains in my testing, the efficiency continues to rise.


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## Widgeon (Jul 17, 2009)

rattus58 said:


> If you understand the exponentialiality, it is fine, but here is the rub...
> 
> grains	400
> speed	350
> ...


I notice that your numbers don't match up with any testing I have done, where did you come up with those?


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## rattus58 (Jul 9, 2007)

Widgeon said:


> I notice that your numbers don't match up with any testing I have done, where did you come up with those?


The only way your numbers could be different is if you used a different rounding. When you say testing, are you refering to speed or what?

grains	500
speed	250
KE	69.37506938
Momentum	0.555000555
momentum_1	5.55000555

grains	1000
speed	125
KE	34.68753469
Momentum	0.555000555
momentum_1	5.55000555

Momentum is force times velociy... that needs to be reduced to some usable form for bullets and arrows. I use a formula that takes grains (1000) divided by 7000 (grains in a pound) times speed divided by 32.175 (approximate acceleration) and then again times 10 to come up with a reference... like 1, 2, or 5.5.

The KE is straight out of the book.


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## Widgeon (Jul 17, 2009)

rattus58 said:


> The only way your numbers could be different is if you used a different rounding. When you say testing, are you refering to speed or what?


Look at the graphs I posted, those are real world numbers I posted, from real bows with real arrows. I'm still asking, where did your numbers come from? To be honest they look made up with the patterns and the evenly spaced weights/speeds in increments all divisible by 5.

Maybe I'm confused at what you are trying to post? Those don't make sense if you are saying they are all shot from the same bow but maybe you attempting something else? Please clarify!


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## rattus58 (Jul 9, 2007)

Widgeon said:


> Look at the graphs I posted, those are real world numbers I posted, from real bows with real arrows. I'm still asking, where did your numbers come from? To be honest they look made up with the patterns and the evenly spaced weights/speeds in increments all divisible by 5.
> 
> Maybe I'm confused at what you are trying to post? Those don't make sense if you are saying they are all shot from the same bow but maybe you attempting something else? Please clarify!


You're not serious are you? They don't make sense? If you've a scale and a chronograph, my friend, and hit my numbers either way... velocity, or weight, the numbers are accurate. They came from table... where do you think they came from.... it's the point of the table, not whether it happens or not, but I will say this... my arrows are 700 grains or heavier. My arrow speeds are in the middle hundred to the best I've ever done, about 205 with my Quillan, but in real life, my arrows definitely accomplish the point of the tables I produced.... meaning, heavy arrows penetrate better than do light arrows.

Tell you what... give me the weight and the velocity of YOUR ARROWS, and I'll come up with a number that is identical to yours... if you measure such stuff... that way...


And as for your table and 700 grain arrow, it was doing 252 feet per second. My momentum values seem to disagree with yours some though... and stick by mine.... how fast was that arrow going?

grains	700
speed	252
KE	98.68531469
Momentum	0.783216783
momentum_1	7.832167832

Aloha... :beer:


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## trapperDave (Mar 12, 2005)




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## IAIS604 (Apr 11, 2010)

The graph trend in Widgeon's data looks correct - momentum should increase with increasing KE.

I also get different values than Rattus. I used the KE formula I gave above, 

KE = 1/2 m v**2

changing grains into lbs (like Rattus), with final units of 
lbs ft**2 / sec **2 (too lazy to do in properly in Joules - but you realize that lbs is not really a unit of mass). I then calculated the momentum (P) from the KE:

KE = P**2/2m

By the formulas, P = MASS x velocity, not force. (I'll leave that exercise to the reader.)

My figures also shows momentum increasing with increasing KE.

As far as rounding goes, there are only 3 significant figures in the mass and velocity data, so any calculation result based on them should give only 3 SF (a KE of 98.7, for example). 

TrapperDave, I'm beginning to agree with your comment!


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## Widgeon (Jul 17, 2009)

rattus58 said:


> You're not serious are you? They don't make sense? If you've a scale and a chronograph, my friend, and hit my numbers either way... velocity, or weight, the numbers are accurate. They came from table... where do you think they came from.... it's the point of the table, not whether it happens or not, but I will say this... my arrows are 700 grains or heavier. My arrow speeds are in the middle hundred to the best I've ever done, about 205 with my Quillan, but in real life, my arrows definitely accomplish the point of the tables I produced.... meaning, heavy arrows penetrate better than do light arrows.
> 
> Tell you what... give me the weight and the velocity of YOUR ARROWS, and I'll come up with a number that is identical to yours... if you measure such stuff... that way...
> 
> ...



I don't disagree that your numbers are correct by the formulas (though I haven't check them myself) I was asking if those are true chronographed numbers coming from a single bow with various arrows. BTW, I don't have an exact 700 grain arrow, you can see in my graphs the discreet points of the actual arrow weights. If you are truly interested, I'd be happy to post all of the arrow weights and their associated speeds for each bow. You can also read my article: 

http://archeryreport.com/2009/11/arrow-kinetic-energy-momentum-archer/

to see how the equations are derived and how I did my testing. Once again I will re-iterate that the numbers I posted are actual numbers from real bows and arrows, not theory (though the data I gathered follows well with the physics theory.) You say your numbers come from a table? What table? How was that table created? What arrows/bows did you use? You can read exactly what I did and how I arrived at it. I have shown through empirical testing that as arrow weight increases, so does momentum and kinetic energy. If you'd like to see my initial testing on penetration, you can read this article:

http://archeryreport.com/2011/03/arrow-penetration-testing-real-bows-real-arrows-real-results/

and see the first results of many to come. You say that heavier arrows penetrate better, yet the numbers you posted show that as arrow weight increases, KE and momentum decrease...explain please. I hold to the theory that in most cases heavier will out-penetrate lighter and I have my testing to back that up. 

Just for kicks and giggles you can even use my calculator to input weight and speed to get KE and momentum:

http://archeryreport.com/calculators.html

Note that this is only for inputting actual speeds achieved with known arrow weights and finding the KE and momentum. It is NOT for predicting of any sort.

I am still really confused as to what you argument really is. Are you arguing that the numbers you show are correct by the formulas? Or are you arguing the the speeds/weights you posted are from a real bow with various arrow weights and it shows the opposite of my data?


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## WindWalker (Jan 23, 2005)

> _Was going to be today, but got postponed for the end of the world.
> _


:teeth::teeth:


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## rattus58 (Jul 9, 2007)

Widgeon said:


> I don't disagree that your numbers are correct by the formulas (though I haven't check them myself) I was asking if those are true chronographed numbers coming from a single bow with various arrows. BTW, I don't have an exact 700 grain arrow, you can see in my graphs the discreet points of the actual arrow weights. If you are truly interested, I'd be happy to post all of the arrow weights and their associated speeds for each bow. You can also read my article:
> 
> http://archeryreport.com/2009/11/arrow-kinetic-energy-momentum-archer/
> 
> ...


My argument is that KE is a function of speed... PERIOD. There is Momentum involved, but momentum is maintained by weight, as is clearly shown by the raft of tables I posted...* to illustrate a momentum value that remains constant* from the original 108 or whatever KE that was, and a 350 fps speed, down to a minimal speed of 182 or something again and a heavier arrow... clearly illustrating that speed has zero to do with penetration other than by coincidence, momentum is wrapped up in it, but not relevant to computation. 

Arrow weight matters for penetration. It just so happens that on most North American animals speed is ok for hunting with light arrows so you don't get to appreciate the power of a heavy slower arrow. The other real time advantage of speed, is trajectory, it is flatter and makes some hunting situations easier to accomodate. But for penetration, it is the weight of the arrow that really matters, and my tables illustrate that fairly clearly... with a constant momentum value for drastically reducing KE.

As for inertia, a heavier arrow is again going to maintain its ability to stay on course over that of a lighter one, as originally posted.


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## tiny52 (Dec 31, 2010)

Funny how I have never seen this at all.
Quite the contrary.

Just yesterday, the wife and I did this same test with her bow while looking for the best penetration.
(we like to fool around like that)

The fastest arrow whooped the heavy arrow at 30 yards and less and the heavy arrows whooped the light guys at 40.
She shoots under 30 when hunting...so we are going light.
(yes...the arrows were of the same diameter and length.)

We already knew this, but just wanted to play with heads and weight....again.
Nothing has changed.




FORESTGUMP said:


> :evil5::nyah:
> 
> I notice from all this that sometimes all the formulas and number juggling can as well be stored under the "thats nice/thank you for that information" heading.
> 
> ...


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## rattus58 (Jul 9, 2007)

tiny52 said:


> Funny how I have never seen this at all.
> Quite the contrary.
> 
> Just yesterday, the wife and I did this same test with her bow while looking for the best penetration.
> ...


Well as Kegan suggested, there is other factors for penetration, but when you say "whooped" heavy arrow, what exactly did you mean? That situation is rarely present in real life with equal sized shafts and the same broadhead, for example..even though you may have significantly different speeds. What were you comparing and what was the penetration into and how much of a "whooping" did the heavy shaft get?


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## Widgeon (Jul 17, 2009)

tiny52 said:


> Funny how I have never seen this at all.
> Quite the contrary.
> 
> Just yesterday, the wife and I did this same test with her bow while looking for the best penetration.
> ...


What were you shooting into to gauge penetration? Was FOC held constant? Where both arrows properly spined and tuned? How did you change the weight of the arrow?


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## Widgeon (Jul 17, 2009)

rattus58 said:


> My argument is that KE is a function of speed... PERIOD. There is Momentum involved, but momentum is maintained by weight, as is clearly shown by the raft of tables I posted...* to illustrate a momentum value that remains constant* from the original 108 or whatever KE that was, and a 350 fps speed, down to a minimal speed of 182 or something again and a heavier arrow... clearly illustrating that speed has zero to do with penetration other than by coincidence, momentum is wrapped up in it, but not relevant to computation.
> 
> Arrow weight matters for penetration. It just so happens that on most North American animals speed is ok for hunting with light arrows so you don't get to appreciate the power of a heavy slower arrow. The other real time advantage of speed, is trajectory, it is flatter and makes some hunting situations easier to accomodate. But for penetration, it is the weight of the arrow that really matters, and my tables illustrate that fairly clearly... with a constant momentum value for drastically reducing KE.
> 
> As for inertia, a heavier arrow is again going to maintain its ability to stay on course over that of a lighter one, as originally posted.


Ok, now I see what point you were trying to prove; I think we were just having a disconnect on communication there. However, running the numbers like you did doesn't tell the whole story because one thing that generally remains constant in these discussions is the bow. That is where my real confusion was in that I've been talking numbers with the bow held constant, you were holding the momentum (and thus not the bow) constant. Sorry for the confusion.

I would certainly not say that KE is a function of speed PERIOD because my numbers prove otherwise. Take the same bow and increase the arrow weight, and what happens? The KE increases, as does the momentum! I also would say that you can't claim weight is the only determining factor in penetration, as there are also issues of penetration that deal with the impulse of the arrow, especially on solid impacts like the bone where speed does have factor (However that is another discussion in and of itself!)

Personally, I believe that the highest contributing factors to good penetration are shot placement, a quality, razor-sharp broadhead on the tip of a properly spined arrow that is tuned as close to perfection as possible. I hunt with what I would consider a mid-weight arrow for my setup because trajectory is also very important to me when hunting speed goats, mulies and elk that tend to be at longer distances than whitetails and hogs. It's up to each individual to asses their own equipment and hunting situations to pick for themselves. The one thing I will always harp on, regardless of the game being hunting and the equipment being used, is that the archery MUST know their equipment and their own capabilities. There is no excuse for going into the field and not knowing how your arrow is going to perform.


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## Kurt Blanken (Apr 12, 2011)

Here is a disconnect: KE is necessary for penetration. A bow with very small KE but a lot of momentum/inertia will just push something out of the way instead of penetrating it. KE is the energy that does the work of moving flesh and bone aside. (Inertia keeps the arrow moving forward while doing this.)

Fluid resistance forces (air) are a factor of velocity squared. Therefore the faster arrows shed more KE in flight than heavier ones. This will explain your results (to a degree) tiny52.

Widgeon, your graphs are confusing because momentum and KE cannot be compared as they are entirely different units. Also the scale is pretty arbitrary.


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## Widgeon (Jul 17, 2009)

Kurt Blanken said:


> Here is a disconnect: KE is necessary for penetration. A bow with very small KE but a lot of momentum/inertia will just push something out of the way instead of penetrating it. KE is the energy that does the work of moving flesh and bone aside. (Inertia keeps the arrow moving forward while doing this.)
> 
> Fluid resistance forces (air) are a factor of velocity squared. Therefore the faster arrows shed more KE in flight than heavier ones. This will explain your results (to a degree) tiny52.
> 
> Widgeon, your graphs are confusing because momentum and KE cannot be compared as they are entirely different units. Also the scale is pretty arbitrary.


The graphs are not meant to "compare" KE and momentum, as there really isn't a way to directly compare them. They simply show the relationship of KE/momentum to increasing arrow weight with KE and momentum on separate axis. The scale isn't as consistent as I'd like it to be, but I struggle with how to best present the pertinent information in as condensed form as possible. I have to write my articles to the general public, most of whom really don't care to dig into the depths of the math but just want to see the trends in the data. When I have written more in depth articles with lots of math and graphs that better tell the story, they tend to get ignored or viewed for a few seconds  However, I am in the midst of doing just such an article on KE and momentum that will be for the engi-nerds and physics geeks that do really care about it, so perhaps you will enjoy them more than the basic graphs I've shown here.


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## rattus58 (Jul 9, 2007)

Kurt Blanken said:


> Here is a disconnect: KE is necessary for penetration. A bow with very small KE but a lot of momentum/inertia will just push something out of the way instead of penetrating it. KE is the energy that does the work of moving flesh and bone aside. (Inertia keeps the arrow moving forward while doing this.)
> 
> Fluid resistance forces (air) are a factor of velocity squared. Therefore the faster arrows shed more KE in flight than heavier ones. This will explain your results (to a degree) tiny52.
> 
> Widgeon, your graphs are confusing because momentum and KE cannot be compared as they are entirely different units. Also the scale is pretty arbitrary.


Explain to me how kinetic energy moves flesh and momentum doesn't have anything to do with it? If you are suggesting that the broadheads blade pushing aside the flesh is "kinetic energy" or work due to kinetic energy, that is one thing... but confusing when you then allude that it is the momentum that makes it all happen, which it is. 

I'm of the opinion, belief and have taken religion to momentum being the KEY to hunting arrows especially on heavy boned animals. My arrows don't zip, but go from end to end when they hit and the only thing "working" is arrow weight.

Much Aloha... :beer:


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## fnds (Dec 2, 2010)

rattus58 said:


> Explain to me how kinetic energy moves flesh and momentum doesn't have anything to do with it? If you are suggesting that the broadheads blade pushing aside the flesh is "kinetic energy" or work due to kinetic energy, that is one thing... but confusing when you then allude that it is the momentum that makes it all happen, which it is.
> 
> I'm of the opinion, belief and have taken religion to momentum being the KEY to hunting arrows especially on heavy boned animals. My arrows don't zip, but go from end to end when they hit and the only thing "working" is arrow weight.
> 
> Much Aloha... :beer:


It's wrong to say that a heavier arrow has more momentum than a lighter arrow, a heavier arrow will have more momentum only if (mass x velocity) is higher. The lighter arrow can have more momentum than a heavier arrow if it is going fast enough. However Widgeon's data suggests that the bows tested impart more KE and Momentum when arrows are heavier. Other bows may behave differently. But we have little (no) data for other bows tested under the same conditions. It would be interesting to see it done for stickbows.

The physics of KE and Momentum are not up for discussion, the real contribution is the data points of arrow weight and speed for a bow. If we had data sets for many bows then we would be able to have a more meaningful discussion based on facts rather than gut feelings.

--fnds


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## rattus58 (Jul 9, 2007)

fnds said:


> It's wrong to say that a heavier arrow has more momentum than a lighter arrow, a heavier arrow will have more momentum only if (mass x velocity) is higher. The lighter arrow can have more momentum than a heavier arrow if it is going fast enough. However Widgeon's data suggests that the bows tested impart more KE and Momentum when arrows are heavier. Other bows may behave differently. But we have little (no) data for other bows tested under the same conditions. It would be interesting to see it done for stickbows.
> 
> The physics of KE and Momentum are not up for discussion, the real contribution is the data points of arrow weight and speed for a bow. If we had data sets for many bows then we would be able to have a more meaningful discussion based on facts rather than gut feelings.
> 
> --fnds


I agree.... lighter arrows have more KE than heavier arrows almost all the time, but that benefit is short lived. Heavier arrows may or may not have high KE, but will have momentum values that will carry where lighter arrows don't. My suggestion is know your equipment and be responsible in shooting your game.


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## ryersonhill (Mar 18, 2006)

Nice debate, these are great, makes you sit and think about what is going on when you release


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## IAIS604 (Apr 11, 2010)

The graphs show that the KE increases with arrow mass (as does momentum) for the bows used.

However note that the increase in KE gain is starting to level off for the heaviest arrows, while momentum continues to rise.
So there is a limit to KE gain (a heaviest effective arrow for a given bow).
Of course, this limit should be much lower for recurves/longbows than the more forceful compound bows the data is for.
Of course, one does not need the math to come to that conclusion!

The goal then, I suppose, is to find the most optimum arrow for your individual bow.

"My suggestion is know your equipment and be responsible in shooting your game." That statement is most certainly true! 

(btw, the different units for KE and P don't matter - we are looking at TRENDS on the graphs)


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## IAIS604 (Apr 11, 2010)

IAIS604 said:


> The goal then, I suppose, is to find the most optimum arrow for your individual bow.


In term of an optimum arrow mass for KE, that is, as well as the usual spine.

"The physics of KE and Momentum are not up for discussion, the real contribution is the data points of arrow weight and speed for a bow. If we had data sets for many bows then we would be able to have a more meaningful discussion based on facts rather than gut feelings." - another most certainly true statement!

Too bad our bows don't come with this data!


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## LBR (Jan 1, 2004)

> The physics of KE and Momentum are not up for discussion, the real contribution is the data points of arrow weight and speed for a bow. If we had data sets for many bows then we would be able to have a more meaningful discussion based on facts rather than gut feelings.


All these fomulas remind me of architects and such. I spent several years working in construction, and you can do pretty much anything you want to on paper, but that doesn't mean it will work in the real world. For example, we had a term for when the blueprints called for an accoustical (drop) ceiling to be hunt from nothing--we needed "sky hooks". The ceiling could be drawn on the plans and look good, but in the real world if there was nothng to attach it to it just wouldn't work. The arechitects would often argue and argue--"it's in the blueprints!"--they put more faith in what was written on paper than the men who did this work day in and day out for years and years.

Looks to be the same thing I'm seeing on this thread, at least in part. Big game guides know their stuff, as do the experienced hunters. Cite one that says the best arrow for a water buffalo is a 500 grain (very fast) arrow shot from an 85# longbow. I don't see it happening. I know lots that will say you are nuts, based on their own experiences. 

The formulas are interesting, but I'll take experience over paper any day.

Chad


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## Kurt Blanken (Apr 12, 2011)

What I am interested in is not the what, but the why.

Rattus: A thought experiment. You have a log. You hang a very heavy wedge from a rope, and put the log lying on its side. You push the wedge into the log. The log will be merely knocked away, because the wedge has momentum but no energy. Send a much lighter wedge much faster and it will stick into the log.

Momentum by itself will simply push the target while deflecting the arrow (conservation of momentum). With KE behind it, the arrow can slice through flesh and break bone. Momentum is still conserved, but energy is not. Either extreme is useless, inertia and KE are both required for penetration.


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## benofthehood (May 18, 2011)

LBR said:


> The formulas are interesting, but I'll take experience over paper any day.
> 
> Chad


What Chad said .....


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## LBR (Jan 1, 2004)

> What I am interested in is not the what, but the why.


The problem, as is made apparant by this thread, is you can get pretty much whatever "why" you are looking for/want to agree with on paper, just like you can hang a ceiling from thin air on paper.

That's the difference in actual real-life experience vs. formulas.

Chad


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## Widgeon (Jul 17, 2009)

LBR said:


> The problem, as is made apparant by this thread, is you can get pretty whatever "why" you are looking for/want to agree with on paper, just like you can hang a ceiling from thin air on paper.
> 
> That's the difference in actual real-life experience vs. formulas.
> 
> Chad


Part of the problem is that many people don't have a fundamental background and/or training in using the physics formulas properly and thus they misunderstand and misuse them. I tend to take it for granted that people should just get it and understand the physics once shown them, but then again it's my life and my job to understand such things. So for me, taking the formulas and applying them to the real world is second nature. It's also why I have done my testing; to study the theory and how it applies to the real world. 

Sometimes I come off brash and arrogant and for that I apologize; it is not my intention. I tend to get wrapped up in the physics of archery because for me, it's fun! It's part of what drives me within the sport of archery and hunting. It's also why I encourage people to better understand what is really happening and take the time to learn a bit more about what is happening behind bows and arrows. 

To tell the truth, penetration is one of the most complicated problems there is. There is so much going on that it's impossible to come up with a simple explanation and conclusion. I understand (nearly) perfectly well what is happening with momentum and KE when an arrow leaves a bow, but when that arrow hits something besides air, it gets all sorts of complicated (and thus fun) because of all of the various things happening. Brittle impact, fluid resistance, impulse mechanics, etc, etc. I just hope that we can continue to have threads such as this that are both education and fun at the same time.


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## voodoofire1 (Jan 24, 2006)

Not quite impossible Widgeon..........Hybrid longbow,[email protected] lever compound,[email protected] than enough for deer, running shoes required for buffalo........


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## BLACK WOLF (Aug 26, 2005)

Widgeon said:


> Part of the problem is that many people don't have a fundamental background and/or training in using the physics formulas properly and thus they misunderstand and misuse them. I tend to take it for granted that people should just get it and understand the physics once shown them, but then again it's my life and my job to understand such things. So for me, taking the formulas and applying them to the real world is second nature. It's also why I have done my testing; to study the theory and how it applies to the real world.
> 
> Sometimes I come off brash and arrogant and for that I apologize; it is not my intention. I tend to get wrapped up in the physics of archery because for me, it's fun! It's part of what drives me within the sport of archery and hunting. It's also why I encourage people to better understand what is really happening and take the time to learn a bit more about what is happening behind bows and arrows.
> 
> To tell the truth, penetration is one of the most complicated problems there is. There is so much going on that it's impossible to come up with a simple explanation and conclusion. I understand (nearly) perfectly well what is happening with momentum and KE when an arrow leaves a bow, but when that arrow hits something besides air, it gets all sorts of complicated (and thus fun) because of all of the various things happening. Brittle impact, fluid resistance, impulse mechanics, etc, etc. I just hope that we can continue to have threads such as this that are both education and fun at the same time.


:thumbs_up

Ray :shade:


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## Widgeon (Jul 17, 2009)

voodoofire1 said:


> Not quite impossible Widgeon..........Hybrid longbow,[email protected] lever compound,[email protected] than enough for deer, running shoes required for buffalo........


Hah! Yes, in some cases the conclusion is pretty easy to come by 

You do bring up and excellent point that often gets overlooked. If you are only going to hunt whitetails, then your setup would be different than someone who is much bigger game. I find that on AT, the vast majority of hunters are only after whitetail and smaller game. I tend to think more on the scale of large elk and longer shots.


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## rattus58 (Jul 9, 2007)

Widgeon said:


> Part of the problem is that many people don't have a fundamental background and/or training in using the physics formulas properly and thus they misunderstand and misuse them. I tend to take it for granted that people should just get it and understand the physics once shown them, but then again it's my life and my job to understand such things. So for me, taking the formulas and applying them to the real world is second nature. It's also why I have done my testing; to study the theory and how it applies to the real world.
> 
> Sometimes I come off brash and arrogant and for that I apologize; it is not my intention. I tend to get wrapped up in the physics of archery because for me, it's fun! It's part of what drives me within the sport of archery and hunting. It's also why I encourage people to better understand what is really happening and take the time to learn a bit more about what is happening behind bows and arrows.
> 
> To tell the truth, penetration is one of the most complicated problems there is. There is so much going on that it's impossible to come up with a simple explanation and conclusion. I understand (nearly) perfectly well what is happening with momentum and KE when an arrow leaves a bow, but when that arrow hits something besides air, it gets all sorts of complicated (and thus fun) because of all of the various things happening. Brittle impact, fluid resistance, impulse mechanics, etc, etc. I just hope that we can continue to have threads such as this that are both education and fun at the same time.


Not complicated at all.... just take one 700-770 grain wood arrow, 1 snuffer, 165 fps at the handle and 22 yards or less.... simple.... :grin:


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## rattus58 (Jul 9, 2007)

voodoofire1 said:


> Not quite impossible Widgeon..........Hybrid longbow,[email protected] lever compound,[email protected] than enough for deer, running shoes required for buffalo........


hahahha..... we only have large pigs here.... :grin:


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## kegan (Aug 28, 2006)

Kurt Blanken said:


> What I am interested in is not the what, but the why.
> 
> Rattus: A thought experiment. You have a log. You hang a very heavy wedge from a rope, and put the log lying on its side. You push the wedge into the log. The log will be merely knocked away, because the wedge has momentum but no energy. Send a much lighter wedge much faster and it will stick into the log.
> 
> Momentum by itself will simply push the target while deflecting the arrow (conservation of momentum). With KE behind it, the arrow can slice through flesh and break bone. Momentum is still conserved, but energy is not. Either extreme is useless, inertia and KE are both required for penetration.


That's just a bad analogy. Especially since experience, at least my own, says differently.

A yer or so ago we were helping some friends do firewood. My brother and I had our own system, but working with others we had to adapt. Normally we use a very heavy maul, a little rotational swing and usually you get split firewood. However, the only thing available to split with was one of those fiberglass handled triangular wedges that weighs about four pounds as that was easy for them to lift. Now, my brother is extremely strong and husky, and even though he could swing that little thing faster than I could follow it by eye, he couldn't split the logs. The head just bounced off. The next day we came back with our own maul, and split the whole pile in about an hour. The slower moving maul made it far easier to split the wood, and with far less energy. 

As for KE breaking bone, there are also lots of accounts of folks using light arrows from compounds going very fast, only to be stopped when hitting the shoulder of a white tail.


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## Eldermike (Mar 24, 2009)

KE is the energy of motion, it's not what you need to know about arrows. Friction/gravity/hard surfaces acts to stop objects, or to eat up all the energy (convert it to heat). Energy is acted on based upon surface area. A car at 2.5 mph has over 36,000lbs of energy but it also has a very large surface area on it's nose. This means very low Pounds per square inch in resistance to stop the car in an impact. But if you drove that same car into a skinny arrow shaped object with sharp point and a perfect angle of entry it would not even slow down. This is based on it's WEIGHT and the ability of that MASS to distribute that energy and lose it to heat based on friction.


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## whitewolf1 (Jun 28, 2006)

Eldermike said:


> KE is the energy of motion, it's not what you need to know about arrows. Friction/gravity/hard surfaces acts to stop objects, or to eat up all the energy (convert it to heat). Energy is acted on based upon surface area. A car at 2.5 mph has over 36,000lbs of energy but it also has a very large surface area on it's nose. This means very low Pounds per square inch in resistance to stop the car in an impact. But if you drove that same car into a skinny arrow shaped object with sharp point and a perfect angle of entry it would not even slow down. This is based on it's WEIGHT and the ability of that MASS to distribute that energy and lose it to heat based on friction.


So if I am ever charged by a water buffalo, shoot it while it is still coming?


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## kegan (Aug 28, 2006)

whitewolf1 said:


> So if I am ever charged by a water buffalo, shoot it while it is still coming?


No, drop the bow and grab your _spear_!


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## WindWalker (Jan 23, 2005)

How 'bout them Cubbies?


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## rattus58 (Jul 9, 2007)

Eldermike said:


> KE is the energy of motion, it's not what you need to know about arrows. Friction/gravity/hard surfaces acts to stop objects, or to eat up all the energy (convert it to heat). Energy is acted on based upon surface area. A car at 2.5 mph has over 36,000lbs of energy but it also has a very large surface area on it's nose. This means very low Pounds per square inch in resistance to stop the car in an impact. But if you drove that same car into a skinny arrow shaped object with sharp point and a perfect angle of entry it would not even slow down. This is based on it's WEIGHT and the ability of that MASS to distribute that energy and lose it to heat based on friction.


???


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## Widgeon (Jul 17, 2009)

Why do people insist on only saying one factor should be looked at to determine arrow performance? Understanding KE and momentum and their associated properties is important to understanding performance. You can't just pick one property and latch onto that with a death grip claiming that it and only it is important.


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## Widgeon (Jul 17, 2009)

Eldermike said:


> KE is the energy of motion, it's not what you need to know about arrows. Friction/gravity/hard surfaces acts to stop objects, or to eat up all the energy (convert it to heat). Energy is acted on based upon surface area. A car at 2.5 mph has over 36,000lbs of energy but it also has a very large surface area on it's nose. This means very low Pounds per square inch in resistance to stop the car in an impact. But if you drove that same car into a skinny arrow shaped object with sharp point and a perfect angle of entry it would not even slow down. This is based on it's WEIGHT and the ability of that MASS to distribute that energy and lose it to heat based on friction.


Arrows aren't moving? Arrows don't use energy? Energy isn't used to penetrate...Kinetic energy?

Secional density is the proper term for the ratio of cross sectional area to weight and it is an important factor in penetration.


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## BLACK WOLF (Aug 26, 2005)

Widgeon said:


> Why do people insist on only saying one factor should be looked at to determine arrow performance? Understanding KE and momentum and their associated properties is important to understanding performance. You can't just pick one property and latch onto that with a death grip claiming that it and only it is important.


:thumbs_up

Ray :shade:


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## Eldermike (Mar 24, 2009)

Yeah they are moving, but what difference does that make, motion is relative. Sectional density is a ratio, that is correct also. I think we are saying the same thing, I am just not doing a great job at it.


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## fnds (Dec 2, 2010)

Widgeon said:


> Why do people insist on only saying one factor should be looked at to determine arrow performance? Understanding KE and momentum and their associated properties is important to understanding performance. You can't just pick one property and latch onto that with a death grip claiming that it and only it is important.


Any object in movement has momentum and kinetic energy. Both depend on mass and speed. It doesn't make sense to single one out when it's obvious that both are present at any time, until speed drops to zero. To be precise, P is a vector and has a direction (velocity), as opposed to KE, which has no direction associated with it.


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## LBR (Jan 1, 2004)

Just out of curiosity...how many of you are actually interested/concerned about penetration because you plan to hunt a very large, very dangerous animal and need all the info. you can get to make a good decision...and how many of you just like to talk about it and compare notes?

I'm planning to go hunting--maybe as soon as next year--for Asiatic Water Buffalo. I need to know what works. I don't much care why, at least as far as formulas go--I'm going to use time-tested and proven equipment. I prefer experience over oratory skills, pretty much with anything I do.

If you just like to compare notes, that's fine with me. I just want to know where you are coming from. 

Chad


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## WindWalker (Jan 23, 2005)

> I'm planning to go hunting--maybe as soon as next year--for Asiatic Water Buffalo. I need to know what works. I don't much care why, at least as far as formulas go--I'm going to use time-tested and proven equipment. I prefer experience over oratory skills, pretty much with anything I do.


Why would you seek the answers here...in this thread? It would make more sense if you sought the answers from sites where such big game hunters gather or from the outfitter(s). That is unless Asiatic water buffalo run wild in Mississippi and you plan to freelance your own hunt or go hunting in a nearby zoo.


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## LBR (Jan 1, 2004)

Don't you love it when someone answers a question with a different, totally unrelated question?


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## WindWalker (Jan 23, 2005)

> Don't you love it when someone answers a question with a different, totally unrelated question?


But very relevant.


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## Widgeon (Jul 17, 2009)

I care about both the theory and actual physics because I am a mechnical engineer and physics junky therefore it is fun for me. I also care about the practical applications becuse I hunt elk and they tend to be on the large side!


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## WindWalker (Jan 23, 2005)

> Don't you love it when someone answers a question with a different, totally unrelated question?


Very relevant. If I am going to hunt elephants for the first time, I'm not going to seek the necessary information and advice from rabbit hunters or base my decisions on posted theories.


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## LBR (Jan 1, 2004)

And that's why I asked my question. I'm not going to base my equipment choice on theories, or on what people who only shoot paper shoot. I don't know if anyone here has actually studied this from the same perspective that I have, or hunted very large game, so rather than assume this or that I asked. 

As I've noted before--on this thread--I've already talked to outfitters, guides, and experienced hunters. I'm always looking to expand my knowledge on topics that interest me. That, along with this thread's topic being arrow penetration tests, makes my question not only relevant but very logical as well. Asking me why I'm asking about penetration experience on a penetration thread is not relevant or logical, IMO.

Chad


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## LBR (Jan 1, 2004)

Thanks Widgeon! As my signiature line states, you are a rare bird!

Chad


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## WindWalker (Jan 23, 2005)

Where do you plan on hunting an Asiatic water buffalo? Big difference hunting and tracking one in a fenced area and in its natural environment.


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## LBR (Jan 1, 2004)

From the rules sticky at the top of the forum.



> DON’T HIJACK THREADS. Stay on the current topic of the thread. Someone has asked a question and needs an answer.


Thanks for your compliance.

Chad


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## rattus58 (Jul 9, 2007)

WindWalker said:


> Why would you seek the answers here...in this thread? It would make more sense if you sought the answers from sites where such big game hunters gather or from the outfitter(s). That is unless Asiatic water buffalo run wild in Mississippi and you plan to freelance your own hunt or go hunting in a nearby zoo.


For one thing, we're talking about Penetration here, and with something like a Buffalo, I'd be tempted to ask here too.

But that is just me... :grin:


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## LBR (Jan 1, 2004)

Thanks Rattus--I thought it was the logical thing to do too, but that's just me.

Chad


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## Sanford (Jan 26, 2009)

rattus58 said:


> For one thing, we're talking about Penetration here, and with something like a Buffalo, I'd be tempted to ask here too.
> 
> But that is just me... :grin:


I think LBR's question was "why" is it being discussed instead of "should" it be discussed here - is it being discussed to discuss penetration dynamics or to discuss penetration of large game? Since the "original topic" was purely one of penetration, i.e., field/target points used in the test, I would answer that "no" it is not a discussion on large game penetration but merely a discussion on penetration. A member's notes on testing (results) are the points of topic.


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## whitewolf1 (Jun 28, 2006)

LBR said:


> Just out of curiosity...how many of you are actually interested/concerned about penetration because you plan to hunt a very large, very dangerous animal and need all the info. you can get to make a good decision...and how many of you just like to talk about it and compare notes?
> 
> I'm planning to go hunting--maybe as soon as next year--for Asiatic Water Buffalo. I need to know what works. I don't much care why, at least as far as formulas go--I'm going to use time-tested and proven equipment. I prefer experience over oratory skills, pretty much with anything I do.
> 
> ...


You already know what works...for north american game, mid weight to moderately heavy with real sharp out front...for them big boned, thick skined mean critters in Oz and Africa, heavy and real sharp and solid out front.


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## WindWalker (Jan 23, 2005)

Who here has hunted water buffalo?


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## rodney482 (Aug 31, 2004)

I can see where LBR's question was relevant to this thread.

I can also see posts that are nothing more than an instigation.

Please refrain from attacks and bashing. 

Rodne482
Site Admin


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## whitewolf1 (Jun 28, 2006)

Sanford said:


> I think LBR's question was "why" is it being discussed instead of "should" it be discussed here - is it being discussed to discuss penetration dynamics or to discuss penetration of large game? Since the "original topic" was purely one of penetration, i.e., field/target points used in the test, I would answer that "no" it is not a discussion on large game penetration but merely a discussion on penetration. A member's notes on testing (results) are the points of topic.


You are right and thus my original question why would anyone do a penetration test without using broadheads of some sort. The purpose of penetration is to reduce some critter to a skillet or grill.


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## Sanford (Jan 26, 2009)

whitewolf1 said:


> You are right and thus my original question why would anyone do a penetration test without using broadheads of some sort. The purpose of penetration is to reduce some critter to a skillet or grill.


To reduce the variables to a specific point of study, I'm sure.


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## whitewolf1 (Jun 28, 2006)

WindWalker said:


> Who here has hunted water buffalo?


North American rhino is the toughest thing I have shot and that is not a suitable comparison. Would like to hear from those here that have successfully taken water buff, what the equipment setup was.


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## LBR (Jan 1, 2004)

I really don't see the relevance if you just shoot foam or paper--they "die" the same with a 1/2" penetration or 12" of penetration.

I don't mind the discussion either way, just curious about it--don't see the point, other than seeing who has better math/physics skills.

On the other hand, if the study is just part of the research required for someone who's never hunted this type animal and is trying to garner all the information they can before making an equipment choice, I fully understand it.

Chad


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## whitewolf1 (Jun 28, 2006)

Sanford said:


> To reduce the variables to a specific point of study, I'm sure.


That was the case of the OP. It still just seems counter productive to me for finding relevant answers to the penetration question. At the end of the day though, imo, to find any sort of answer you would have to break out the testing by bow designs, a range of total arrow weights, fletching considerations and broadhead designs. Is all of that needed for what most of us hunt here in NA, prolly not. But I think it would shed a better light on how best to setup a particular rig for a hunting application. In my mind, Dr. Ashby's studies set a bar for the high side extreme of hunting application and that is great but where is a reasonable low side? 

Would you recommend a 7.5 gpp arrow with a big 3 blade snuffer to a guy wanting to hunt whitetails with a 40# D longbow? 

That is where I think penetration and bow efficiency testing are also important.


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## LBR (Jan 1, 2004)

> ...but where is a reasonable low side?


To me, that's where the rub comes in. You start talking about being able to cleanly kill an elephant with a .22 rifle, some knucklehead is going to try and do it with a Daisy "Red Ryder" bb gun, just to try and 1-up the .22 guy.

IMO, we don't need to push the limits on the low side. I understand that some would say that's exactly what I plan to do when hunting a water buffalo with a bow. I don't think so. If I were planning to hunt one with a 40# bow that would be the case, but it's been proven time and time again a bow and arrow combo set up for this type animal will kill it just as quickly and cleanly as a well-placed slug from a double rifle--maybe moreso.

There's a ton of variables to consider, and people tend to do stupid things. If you don't have a clue what you are doing, you can have problems getting decent penetration on a whitetail shooting 80+ lb bows...and we know that someone who knows what they are doing can shoot clean through a whitetail with less than half that much draw weight.

Besides that, releases can vary, especially when the temps drop, when excitement levels rise, etc. and I wouldn't want 1 or 2# of draw weight or 5 fps be the difference in a clean kill vs. a wound.

That's why I'm not comfortable trying to guage what's the least we can get away with. I rather keep it on the other side, at least for hunting.

Chad


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## whitewolf1 (Jun 28, 2006)

I absolutely agree with not pushing the limits on the low side and that is why I think having a better understanding of things like bow efficiency and penetration are important, so we dont push that limit too much.

Here in AR we have, or atleast the last time I checked, a minimum of 40# draw weight. There is no disctinction on bows, just a weight. Maybe I am just different but my recommendations for a hunting setup at 40 pounds will certainly vary across bow types, maybe not a lot but certainly some. And they would certainly not push the envelope of what you could get by with under perfect conditions.


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## LBR (Jan 1, 2004)

Ok--we're on the same page then. I agree--just listing a poundage won't solve much at all, but it could get too complicated for the game wardens to begin to enforce.

I like it when states have a rule about a bow having to cast a certain arrow a certain distance to be legal...but how is the game warden going to check that in the field? Just not practical, although it's a better standard than draw weight alone.

Chad


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## BLACK WOLF (Aug 26, 2005)

whitewolf1 said:


> North American rhino is the toughest thing I have shot and that is not a suitable comparison.


North American Rhino??? Sorry for my ignorance...but what is that? I've never heard of one of those before.

Ray :shade:


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## whitewolf1 (Jun 28, 2006)

BLACK WOLF said:


> North American Rhino??? Sorry for my ignorance...but what is that? I've never heard of one of those before.
> 
> Ray :shade:


Porkers. We have or atleast had lots of them before all the flooding going on. Biggest ones killed in my area have been in the 300-350# range. I have seen one I thought would make 400+ with no problem and had him broadside at 18 steps but my bow was on the wheeler. I stood real still. I have yet to kill a big one but I aint givin up.


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## BLACK WOLF (Aug 26, 2005)

whitewolf1 said:


> Porkers. We have or atleast had lots of them before all the flooding going on. Biggest ones killed in my area have been in the 300-350# range. I have seen one I thought would make 400+ with no problem and had him broadside at 18 steps but my bow was on the wheeler. I stood real still. I have yet to kill a big one but I aint givin up.


LOL.....ahhhh...I had a feeling it was another name given to our pigs  I'm sure your desitined to get a monster at some point.

Ray :shade:


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## Van/TX (Jul 20, 2008)

LBR said:


> All these fomulas remind me of architects and such. I spent several years working in construction, and you can do pretty much anything you want to on paper, but that doesn't mean it will work in the real world. For example, we had a term for when the blueprints called for an accoustical (drop) ceiling to be hunt from nothing--we needed "sky hooks". The ceiling could be drawn on the plans and look good, but in the real world if there was nothng to attach it to it just wouldn't work. The arechitects would often argue and argue--"it's in the blueprints!"--they put more faith in what was written on paper than the men who did this work day in and day out for years and years.
> 
> Looks to be the same thing I'm seeing on this thread, at least in part. Big game guides know their stuff, as do the experienced hunters. Cite one that says the best arrow for a water buffalo is a 500 grain (very fast) arrow shot from an 85# longbow. I don't see it happening. I know lots that will say you are nuts, based on their own experiences.
> 
> ...


Me too:set1_signs009:...Van


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## Van/TX (Jul 20, 2008)

Eldermike said:


> KE is the energy of motion, it's not what you need to know about arrows.


Agree. A .22 rimfire produces more KE than any trad bow that any mere mortal could shoot. It will kill deer but is not a popular choice. A large animal would think it got stung by a bee if it even noticed...Van


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## Van/TX (Jul 20, 2008)

LBR said:


> Just out of curiosity...how many of you are actually interested/concerned about penetration because you plan to hunt a very large, very dangerous animal and need all the info. you can get to make a good decision...and how many of you just like to talk about it and compare notes?
> 
> I'm planning to go hunting--maybe as soon as next year--for Asiatic Water Buffalo. I need to know what works. I don't much care why, at least as far as formulas go--I'm going to use time-tested and proven equipment. I prefer experience over oratory skills, pretty much with anything I do.
> 
> ...


Wow! Good luck on your hunt. That's cool...Van


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## LBR (Jan 1, 2004)

Hey Van--welcome aboard! 

Chad


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## Van/TX (Jul 20, 2008)

Thanks Chad. I registered a few years ago but just forgot about this place until someone mentioned it on another site. This is a good one for sure...Van


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