If you're using an adapter for screw in broadheads, you pretty much won't see a difference in penetration. And the difference in wind drift is tiny. The difference in stability is bigger than the other two factors IMO. If your 5mm setup is plenty stable and accurate, there's not a noticeable improvement inside of 60 yards. Difference in drift at 80 yards is like an inch or so in 5-10mph winds.

I love 4mm shafts, but the only components I like for them are the Valkyrie stuff. I've been sticking to the 5mm stuff because the difference in flight isn't big enough for any distance I can ethically hunt in.

 

Thanks for your input. I am not at all unhappy with my setup or have found issues with it. I guess I am just chasing perfection when it comes to hunting. I want to provide the quickest death I possibly can to an animal and I want my equipment and my skills to be at their best. That is what I am chasing and that is why I like to tinker with things and I'm never satisfied lol. I don't want to shoot a shot that is "good enough" you know?

 

Agree with above. The wind drift is insignificant between 4mm and 5mm. I live in Wyoming. I know wind.

 

Thanks for the information. I guess now I can gather information on what is the lightest arrow anyone has hunted with successfully.

 

I'd stick with what you got less hassles with components generally, so maybe a change up of 5mm flavoring of shafts is in order? You don't say who's shaft you are using currently, easton sonics 340 with 7.8gpi drops your gpi by an 1gn compared to your 4mm and possibly giving you some wiggle room. Also, somewhere bwtn 400gn and 425gn provides the most kinetic energy at your DL and poundage if your interested in the kind of stuff. Would imagine since you didn't mention what bow that you'd likely be around 275fps at 400gn, and 265 at 425gn.

I would at a minimum for elk use a 125gn coc broad head as they are usually built tougher when compared to their lighter offerings.

 

I am currently shooting RIP TKOs
Is there a calculator you recommend that will give me an average of what speed I'm shooting at? I'll attach a picture of my setup

 

Before I bought a scale to weigh things, I had shot several elk with a 385 grain standard arrow with 100 grain or 125 grain Thunderheads out of First- 1988 Browning Mirage Compound 70lbs at 30 inches later with a PSE Diablo 60lbs 305ibo 28 dl

arrows were X-weaves right off the shelf with standard insert and 3 inch duravanes
the last bull I shot was with a PSE Inertia 60lb 28dl 345 ibo with same 385gr arrows with a 100 gr HellRazor

no need to change what you have now

 

Great! That gives me confidence that I am probably solid on my arrow builds 😁

 

I put 400 grains right they a few bulls. 378 thru elk cows, deer and 200# pigs

 

To me, you have the perfect setup already and will not notice enough difference for the change up and definitely not worth the hassle of 4mm components. Good luck!!

 

Nice shafts, would get the job done. I've used the calculator below, should give you an opportunity to play with your numbers a little.
calculator

 

20 ish grain difference is not much. My last elk was taken with 430 grains and 64 pounds, granted a 30.6 inch draw.

I took a red stag ( a bit smaller than elk with a 350 grain arrow and same set up)

in both cases I used cut on contact

women and teens with short draws and lower poundage can kill elk just fine albeit they must be at closer ranges.

I think you are good either way.

 

With the Op's TAW & point weight choices, What broadhead allows the most confidence & what would a ethical, thoughtful, hunter shy away from & why?

 

On elk? I'd avoid most mechanicals. Many fixed blade options would work, but at 100gr you'll be hard pressed to find better than the Kayuga pilot cut, any VPA, or Cutthroat. I don't like Iron Will heads, but that's another conversation.

Anything metal injection molded is also a hard no (Montec, NAP, etc). The only replaceable blade I'd even consider would be a Magnus. QAD Exodus is tough, but if you don't have the power to shatter a bone you could be left wanting on penetration.

Gimmick heads and Ramcats should be avoided because they aren't durable enough. Ramcats just won't stay sharp after all the stuff in elk hide. Most replaceable blade heads have similar issues. I put most Swhacker heads in this category as well.

I don't think Tuffheads do anything special unless you get up there in weight. I'm similarly unimpressed by Bishop.

@Jon90, whatever you buy just make sure you sharpen it yourself. Never trust a factory edge.

 

Every single guy I know that lives in Colorado, Utah & Montana use mechanical broadbands and they all use 400-450gr arrows!

Heck one body that lives in Colorado his wife drew a Colorado moose tag!!! She shot a massive moose with a 27" draw 48lb 1⅜" grimmreaper expandable with a 430ish grain arrow and the broadhead was sticking out the opposite side!!

#1 thing that they all say is that you have to make them bleed!

 

Every single guy I know that lives in Colorado, Utah & Montana use mechanical broadbands and they all use 400-450gr arrows!

Heck one body that lives in Colorado his wife drew a Colorado moose tag!!! She shot a massive moose with a 27" draw 48lb 1⅜" grimmreaper expandable with a 430ish grain arrow and the broadhead was sticking out the opposite side!!

#1 thing that they all say is that you have to make them bleed!

Holy hell that's amazing. Thanks for the information man. I feel like I am will be fine. I am practicing a ton so when the time comes I make it count!

 

I tend to stick to 500ish gr TAW because with my draw length and weight, that usually puts my speed right around where I want to be. I primarily shoot fixed blades. I prefer my arrow speeds to be somewhere in the 275-290 neighborhood. However, this year I will be hunting with a significantly lighter arrow. I built some RIP XVs that finished at 425 gr total. That's the lightest I have gone.

I honestly don't think you're going to see much of a difference between 5mm and 4mm shafts. I'm not saying you shouldn't switch to 4mm shafts. I shoot VAP SS, Valkyrie Reigns, and Sirius Orions. I just don't think the difference will be enough to justify the cost of buying new arrows. With that said, if you just want to buy new arrows to tinker then go for it.

 

Most of the time, we look for reasons to tinker. There wont be a big difference at all in those setups but if you got the money and the time to play with it, have fun. Thats what this is all about. I'm right there with you as far as 27" draw and I ran the Axis' arrows at 432 grain and now I use the tko at 425. No other reason than to just have something different. Your arrow weight isn't what makes you a responsible and ethical hunter, it's your shot choices.

 

Very well said. I posted the same question on rokslide and I think I am gonna go with an arrow closer to 450 grains. I am now certain I can kill something with a 400 grain arrow but it seems like the lighter an arrow is, the better the placement of your shot has to be. It seems to be the consensus that a heavier arrow could be more forgiving if your shot isn't as perfect as you want it to be. Thanks very much for your input!

 

Above numbers are at 27.5" draw length 62# if I remember right. 26.5" bare shaft arrows in 3 different weights you will get an idea what your speed will be like (alpha x 33)

 

Respectfully, my goal is not to hear about why you only shoot 500ish grain arrows. I want to know what's the lightest arrow people have hunted elk with. I am planning on building new 4mm arrows and without having to buy heavier broadheads and/or heavier inserts that don't already come with the arrows, I will end up somewhere around 403 grains with 3 fletch aae max stealth vanes. Is 403 too light? My current setup is at 425 grains but in all honesty I don't know if 403 is too much of a difference.

My reasoning behind going from 5mm to 4mm is more penetration and less wind resistance. Is it even worth changing my setup in your opinion?

8.3 GPI for 340 spine at 26 inch arrows
8.8 grain vanes
100 grains BH
55 grain insert
6 grain nock
= 403 grains

If it's important, I am shooting 65 lbs with a 27 inch DL

This video does a nice job explaining what is needed and bottom line, you can use 403 or 425 and be successful

https://www.archerytalk.com/threads/arrow-momentum-speed-deprivation-testing.6254711/

 

Magnus stingers would work really well for you and your setup.
Lucky

 

One of my customers took a dandy of a bull with a ~ 415gr arrow. (if I get permission, I'll share the pic) I don't think the extra 15gr in his arrow made the difference between an ethical kill and not.

I'm not an elk hunter but I wouldn't think twice about hunting anything in North America with my set up.

Athens Elevate - 65#/28.5"
Kill'n Stix PT 300 - 30" (TAW 450gr)
Tooth of the Arrow XL - 125gr

 

Respectfully, my goal is not to hear about why you only shoot 500ish grain arrows. I want to know what's the lightest arrow people have hunted elk with. I am planning on building new 4mm arrows and without having to buy heavier broadheads and/or heavier inserts that don't already come with the arrows, I will end up somewhere around 403 grains with 3 fletch aae max stealth vanes. Is 403 too light? My current setup is at 425 grains but in all honesty I don't know if 403 is too much of a difference.

My reasoning behind going from 5mm to 4mm is more penetration and less wind resistance. Is it even worth changing my setup in your opinion?

8.3 GPI for 340 spine at 26 inch arrows
8.8 grain vanes
100 grains BH
55 grain insert
6 grain nock
= 403 grains

If it's important, I am shooting 65 lbs with a 27 inch DL

I have a 27.5" draw length and have ranged through arrow weights of 380 to 440 over the years (I started elk hunting around 1993 or so). Speed has ranged between 250 fps to about 270 fps.
With arrows in that weight range, and a fixed BH, the only shots I'll take are broadside to slightly quartering. A center lung shot through the ribcage has always been a pass through for me.
Hit the scapula, that is a different story. It absolutely is not a setup that you want to hit heavy bone with. I have hit two too far forward over the years. One barely got enough penetration for the BH to be under the near side skin, the other I somehow got lucky and it made it through and got about 9" of arrow into it. I was able to give that one all night and recovered it the next morning. Divine intervention if you ask me.

This last season I shot one at 27 yards with a 425 grain arrow tipped with a 1.5" Sevr, doing 270 fps. Arrow only hit one rib on the exit. It went through, but not with the authority that I normally see with a fixed BH. I feel it would've been sketchy on getting a pass through at 40 yards or more. Will be bumping up my arrow weight up some more for the Sevr's.
Still don't want to get anywhere near a scapula. And I avoid frontals as well, just no confidence in getting good penetration if I miss the mark a bit on that shot.

So, will it work? Yes. But makes for a limiting setup for what shots you should take.

 

unless shooting past 60 yards I have not seen any difference in wind drift from 6mm to 4mm shafts. I don't think you will really see any difference in penetration either I have no way to test that. Even at longer yardages there is not enough difference in wind drift to be very noticeable. your current set up will probably penetrate more or the same as the smaller diameter lighter arrow you are looking at going to.

 

I've been Bowhunting for 4 decades....shot every setup under the sun and hundreds of critters.

My current hunt arrow, 435g with a 2 blade in a 53# recurve.

 

I hope that after 4 decades I too will have the blessing of shooting hundreds of critters. I am just going to try to add 20 lb back weights to my current setup. Thanks very much for sharing

 

265gr VAP
120 gr Deep 6 RamCat Broadhead and insert
Total weight 385gr
Killed my bull just fine....