# need HELP understanding arrows



## Six Shooter (May 22, 2008)

Does anyone know of a link or a place I can find arrows for dumbies info??? Things like what proper spine means, gpi, the numbers on arrows 5575, 500 etc. Any help would be great. Thanks


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## 3dshooter80 (Mar 13, 2006)

I will see if I can help. Proper spine is the optimal stiffness that an arrow has given a set draw length and draw weight. Each arrow company has their own way of indicating spine, but ultimately they are all based on Easton's ratings. Easton is the gold standard for arrow spine as they use actual spine deflection numbers. The procedure for measuring spine is to hang a 1.94 lb weight from the middle of a 28" length of arrow shaft and to measure how far it deflects or sags. A spine of 500 means that it deflected .500" and a 340 is .340". The standard spines for hunting arrows in carbon arrows are 500, 400, and 340. These are the most common, but they are only a small part of the spine ratings. 
Carbon Express chooses to use a 150, 250, 350 system where the 150 correlates with a 500, 250 is a 400, and 350 is a 340. Gold Tip uses 35/55 which is a 500, 55/75 is a 400, and 75/95 is a 340. Easton produces aluminum shafts and aluminum/carbon shafts of many different ratings and they usually have their own shaft identification number in conjunction with the spine rating printed on the shaft. They have actually just started doing this with aluminum shafts in the last year or so. 
When looking at aluminum shafts, there is a 4-digit number that identifies each shaft. Take a 2213 for example. The outer diameter is 22/64" and the wall thickness is .013". A 2712 is 27/64" and .012" . 
I would suggest that you spend some time looking at Eastons spine chart on their website. You will see that as length or weight increases, the spine number decreases. The reason the spine number gets smaller is that as the shaft gets stiffer, it deflects a smaller amount given the same 1.94 lb weight hung in the middle. It seems counter-intuitive but it is a good system.


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## Six Shooter (May 22, 2008)

Thanks Bullwinkle this was very helpful..


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## smartwick08 (Feb 9, 2010)

yea this helped me out alot too thanks


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## YZ125MM700 (Dec 30, 2009)

Very helpfull, thank you. I wish everyone could be as helpfull as you without bashing people because they dont have a million post's.


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## 3dshooter80 (Mar 13, 2006)

I have had a hard time getting answers in the past and I try to help people as much as I can. I am glad that I could help.


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## corps (Dec 24, 2009)

*Thanks*

That helped me alot as well.


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## docarcher (Nov 30, 2009)

I found this site to be particularly useful, for arrow info, bow info, etc.

http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_1.htm


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## bowhunterprime (Jan 28, 2009)

docarcher said:


> I found this site to be particularly useful, for arrow info, bow info, etc.
> 
> http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_1.htm


+1!!!!

When I found Hunters Friend I thought I had hit the information jack-pot!! Then I found AT  !!!!! -Chris


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## AKRuss (Jan 10, 2003)

One of the best references is Easton's "Arrow Tuning and Maintenace Guide." I think they still have it on their website or you can google it up elsewhere.


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## ajstrider (Feb 20, 2009)

To continue on answering your questions...

So spine numbers have been defined, but to help explain what spine does for you. Your arrow needs to flex a certain amount, but not too much. So the higher spine deflection, for example .500", is for use in lighter pull bows and/or short draw lengths, since they do not transfer as much energy to the arrow, it needs to be a bit more flexible to allow that small amount of energy to flex it. A .340" spine is for use with heavier poundage and/or long draw length bows since they transfer more energy to arrow, it will not need to be as flexible since the extra energy will take care of it. Each manufacturer has a chart for its arrows and associated arrow lengths/bow poundage to help you figure out what spine you need. The downsides of having too light (.500" when the charts call for a .340") of spine is the arrow may flex to the point of fracture when you shoot your bow. Now this is an extreme case, normally going one spine deflection size lighter doesn't really present any danger that I have seen. Having too heavy of spine doesn't present any dangers but will sometimes make the bow hard to get into tune because your arrow is not flexing like it should. A heavier spined arrow is generally going to be a heavier GPI (grains per inch) which tells you how much your bare arrow shaft is going to weigh. Weight is another personal preference, but the bare minimum is generally considered to be 5 grains per pound of draw weight, so a 60# bow should have at least a 300 grain arrow, now that weight is overall weight once the arrow head and vanes are added. IBO speed is figured up with a 70# bow, 30" draw length, and a 350 grain arrow for this reason I guess. Fast, light arrows have advantages, and slow, heavy arrows have advantages. They are personal choices I guess and would create a whole separate discussion.


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## Six Shooter (May 22, 2008)

*Thanks*

To all of ya who have taken the time to help me with my question THANK YOU very much. I knew I joined the right forum..


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## Bird Dogg (Aug 18, 2009)

*hate that*



YZ125MM700 said:


> Very helpfull, thank you. I wish everyone could be as helpfull as you without bashing people because they dont have a million post's.


I say this to people who bash:
Its because I spend more time behind my bow and less time on my computer.


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## ajstrider (Feb 20, 2009)

Time behind the bow and experimentation is the best way to figure stuff out. I am about as stupid as a box of rocks, but I spend time figuring stuff out with my bow, even if it is contrary to what people say.


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## Bird Dogg (Aug 18, 2009)

*time behind it*

been shooting so much lately I feel like my arm is going to fall off:
have a vegas paper league every tuesday. 3d league on wednesdays:. might shoot a friday 3d league...shot harrisburg indoor nationals last week, and just competed in springfield yesterday, and then a four spot tournament last night, fatigue showed up in the form of a 295 30x finish, could barely hold the bow... and I only have a little over 200 posts...maybe when I get my posts up to a thousand Ill shoot better... lol....
want as much competition and practice before worlds as I can get


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## Rhody Hunter (Jul 14, 2008)

bowhunterprime said:


> +1!!!!
> 
> When I found Hunters Friend I thought I had hit the information jack-pot!! Then I found AT  !!!!! -Chris


x3 i was going to post the same thing . do all the chapters of the university 
and you will get some great info


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## kardkutter88 (Jun 5, 2010)

This is all very useful info.


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## CFGuy (Sep 14, 2012)

Resurrecting another thread here, but is there any way one could compensate for too weak or too stiff a spine? I.e. my bow at the draw weight calls for a .340 spine, but my arrows are .400 carbon arrows. Is there any way to get these arrows to the minimum required weight (8GPP) while compensating for the spine?


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## wolfman_73 (Mar 7, 2005)

@cf, you could drop point weight, add a wrap, or just turn your bow down a couple turns if it's not already. Dropping point weight or adding a wrap will slightly affect the spine of a 400 to appear stiffer, but turning the bow down to the proper weight for arrow will work as well


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## CFGuy (Sep 14, 2012)

Thanks, good advice. What about using tube weights to bump up the total arrow weight and lower the point so the arrow isn't too light?


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## RdRcr150 (Sep 29, 2012)

I have a #55 Bear Kodiak Magnum recurve so I should use a 340 spine aluminum shaft...correct?


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## Captain Anvil (Dec 7, 2011)

docarcher said:


> I found this site to be particularly useful, for arrow info, bow info, etc.
> 
> http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_1.htm



This is what I read to learn about arrows. Highly recommend it.


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## Captain Anvil (Dec 7, 2011)

RdRcr150 said:


> I have a #55 Bear Kodiak Magnum recurve so I should use a 340 spine aluminum shaft...correct?


We also need to know the arrow length and tip weight you will be using. Aluminum or carbon doesn't matter, and most will recommend carbon.


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## RdRcr150 (Sep 29, 2012)

28" 125gr


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## Captain Anvil (Dec 7, 2011)

By looking at this, follow your draw weight (55) over and find your length (28) in the table of the tip weight you have (125gr.) 55 lbs is in between 2 rows, but they both end up being the tan color, which at the top, represents a spine deflection of *.400*.


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## RdRcr150 (Sep 29, 2012)

Thanks!


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## matteo323 (Oct 2, 2012)

That bit of info really helped being a newbee in archery there is alot of info to understand thanks


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## rhythmz (Jan 10, 2010)

docarcher said:


> I found this site to be particularly useful, for arrow info, bow info, etc.
> 
> http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_1.htm


x4, excellent resource!!!!


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## Atlshaun (Mar 25, 2013)

Hate to bump an old post but thanks to everyone in this thread...my head was exploding trying to figure out the arrow info I learned because of this thread.


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## Wrestler21x (Jul 16, 2015)

Great info thanks guys


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## b0w_bender (Apr 30, 2006)

Yup Hunters Friend is an extremely well written and relatively comprehensive source. It seems like I post that link in about 60% of my posts on this thread. What impresses me most is that they limit their information to that which can be demonstrable. There isn't a whole lot of stuff like _"these feel real smooth"_ sort of language. Just the facts mam just the facts...


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