Simple Arrow Penetration Test Heavy vs. Light

[MilDotMaster]

I just completed a simple test with two types of arrows.

Type "A" carbon arrows were 396 grains total weight with a .295 outside diameter .400 spine at approx 290 fps.

Type "B" carbon arrows were 443 grains total weight with a .302 outside diameter .300 spine at approx 280 fps.

Both type of arrows were shot from the same bow, set at thesame drawweight (63 pounds),at the same 10 yard mark into a foam target.

After shooting numerous arrows... type "A" arrows averaged 1.25 inches deeper penetration into foam target.

I have been hearing all this talk about heavier arrows having more "momentum"withbetter penetration, so I went out and purchased a $100 dozen. From this test I did, I'm seeing the opposite.

Only two things I can think of is the slightly larger outside diameter may be causingenough resistance through the foam, to out weigh the benefits of the momentumfrom the heavier arrows, or thebenefits of the heavier arrowsare only seen at longer ranges.If this is true, it sounds like to me that hunters that make their shots at closer ranges would be better off with the lighter arrows. Maybe I should try the same test at 50 yards. What are your thoughts?[:@]

[Paul L Mohr]

I have done the same test you did but come up with different results. The test is flawed right from the get go because foam targets are very poor mediums to test penitration on because of the way they stop an arrow.

Also the differences in your arrow weights were not very large either. Both were relitively heavy arrows and fairly close in weight.

I have done this test repeatedly with extremes of 100 grns or more and the heavier arrows always hit the the target harder, which would mean more penitration on live game with a blade type head.

Paul

[Sylvan]

I think it's extremely difficult to do a meaningfull test like this. Even the difference you have in spine could explain your apparent contraditory results with accepted physics. If the spine is different then the "tune" is different and therefore at close range the angle the arrow strikes the target is different. It would be interesting to do the down range test as you suggested. That should tend to eliminate tuning differences but then again it's still very difficult to control all the variables in a test like this. I'd rather just trust the physics. Heavier arrows mean a higher percentage of transfer of stored energy to kinetic energy. Thatis not only true in theory but also easily confirmed in tests andhas beenrepeatedly. Pick up a copy of Bowhunter or any mag that does testing and you will find that efficiency and therefore ke and momentum always increase with arrow weight. All things being equal, more energy/momentummeans more penetration than less and that's what you get when you go to a heavier arrow.

[gibblet]

sylvan, where you been?

[Sylvan]

sylvan, where you been?

Hey there gibblet! I've been playing around in some of the other forums but still come here from time to time. Nice you remembered me! Thanks!

[D.Parsons]

distance will definetly tell you a little more.But as stated these 2
arrows are close to weight!

[gibblet]

well, good to see you posting. there have been a couple threads i really wish you had seen and posted on. could have used your input, and a couple would have made you spit your coffee on the computer. there was one in particular about shooting from a treestand that cracked me up to no end.

[Arthur P]

Stuff some yellow Carbon Express weight tubes down the heavy arrow to make a greater weight difference.

I saw a comparative penetration test for handgun bulletsin a gun magazine some years back. The guy didn't have enough money to buy enough ballistics gelatin to conduct the number of tests he wanted to do, so he built a trough out of 2X4's and plywood, seems like he said it was 15' long, but just wide enough and deep enough to hold gallon size freezer bags full of water.

He shot through the bags and counted how many bags got busted by the bullet before it stopped.

Since animals are some 70% water, seems like that would be an excellent medium for doing these penetration tests. As far as I know, ain't a critter in the world made out of foam - except those 3D's. And they don't barbeque up too good. [:'(]

I've kinda missed ya too, Sylvan. We've got ahistory of saying exactly the same thing but in a way that sounds like we disagree with each other.

[Sylvan]

As far as I know, ain't a critter in the world made out of foam - except those 3D's. And they don't barbeque up too good. [:'(]

And its a real pain cleaning the grill when you're done. That stuff gets really sticky when you heat it up! Thanks for the welcome back Art and gibblet. I truly appreciate it!

[muzzyman88]

I think I proved to myself a couple weeks ago that all of this penetration talk is blown way out of proportion. I made a mistake while learning to shoot a back tension release and the bow went off prematurely. Well, the arrow struck the 3/4 plywood that covers the lights. The arrow went almost completely through the plywood covers.

All this at 57lbs, 28" draw and a 370gr arrow.