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Comments

mike
06/21/2010 18:45

I really thought there was a lot of good info there, but what is meant by standard deviation?

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Glenn Lloyd
06/26/2010 10:48

Surprised at your test results. Would have thought heavier arrow = greater penetration...interesting.
Could you give info on arrow diameter? Could this have had an effect? Or maybe surface finish?
This stuff is fascinating to me...
What's your take on reason for result...any ideas?

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mike d
07/15/2010 06:26

very interesting. I would have thought for sure that the heavier arrow would have retained more momentum then the lighter faster arrows. If all was equal (fletching size/diameter..etc) then the only things that i can think that would have given you the outcome would be the following.....

1-The FOC (front of center) of the arrow could have altered the penetration

2-Arrow tuning...if the heavier arrow was not flying straight it would have lost some KE and momentum before and during impact.

the 280g arrow was then one that confused me. The other 2 compared to the heaviest arrow were what i suspected. Need to know what that arrow was so i can start shooting them.

Thanks for the test!

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Joe Crawford
01/06/2011 23:24

Right on!!!! No need to fight!!!! Shoot what is best for you. These folks need to realize what works for them may not be what works best for the other folks. I like to shoot light and with over a 150 deer under my belt I can say it works!!!!! Great job and the old saying is true!!!! The proof is in the pudding!!!

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Roy Marlow link
04/09/2011 09:03

Hi Ike,

Just happened upon your video and website. A few comments on the results of your arrow penetration tests.

The physics of penetration say that--all else being equal--heavier projectiles penetrate bettern than light projectiles. A host of professionally conducted tests on arrows and other low-speed projectiles confirm this. (Check out my book, Archery Ballistics, on the above website for details.

Your 407-grain arrow penetrated better than the 245-grain arrow at all distances except for 10 yards. I suspect that they did not do as well at 10 yards because light, fast arrows have more drag which helps then to straighted out faster at short distance and hit the target more square-on. This has been a biasing factor, that masks the true results, in other arrow penetration tests.

I don't care what a person shoots but feel that they should make decisions based on scientific facts. Your results could cause people to choose light arrows for the wrong reasons, unless this biasing factor is explained to them.

Good luck in all of your furture pursuits.

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Roy Marlow link
04/12/2011 07:53

My earlier email was done quickly and contains some incomplete information.

All else being equal, impact energy and momentum determine penetration. When shot from the same bow, heavy arrows have more of both. In addition, light arrows have more drag due to both their lighter weight and greater speed, causing them to lose a higher percentage of their launch energy and momentum as they travel downrange.

Energy is most important when penetrating “hard” targets but momentum is more important when penetrating “soft” targets. Your measured penetrations at forty yards, into a relatively hard target, were only slightly different for the various arrows but the penetration of your 407-grain arrow into a deer’s soft tissue would be significantly greater than the 245-grain arrow due to its far greater impact momentum.

My book, Archery Ballistics (www.Strikepoint-Press.com), goes into more detail on this and other important shooting issues.

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botech link
05/19/2011 18:54

Very good stuff.
This is just what I saw some years ago during laboratory testing at N.A.P.

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