Testing arrow penetration with 2 different setups

[Nativestranger]

Setup A 400 grain arrow 151 fps

Setup B 300 grain arrow 185 fps

Speed verified with chronometer. Setup A has 33% more arrow weight and ~10% more momentum. Setup B has ~15% more KE. Which do you think will provide more penetration into hard medium like bone? Will be testing them on 3/4" plywood.

[kevsuperg]

OK, I'll guess, ummm A the heavy slow arrow. And that's just cuz I like heavy slow arrows.  I like momentum over speed

[highlow]

Gotta see this.

[Blackhawk]

I'm no Sir Issac Newton, but my gut reaction is to say that "B" wins at close range (under 20 yds) and "A" wins at the longer distances.

[Scott Barr]

I cheated.  Gold tip Kinetic energy calculator gives the nod to B.  But I think Lon has a good point.  Looking forward to your test results.  Scott

[awbowman]

I'll guess that inside 15-18 yards B, outside 15-18 yards A?

Oops, didn't see Blackhawk's post.  X2 on Blackhawk's prediction

[Zradix]

Depends on the yardage and foc

[JohnV]

Neither.  Both setups are generating little kinetic energy and momentum.  I would not want to use either setup for big game animals.

[kevsuperg]

Native, hurry up and shoot something so i know if I won .  
 PS, i agree with John v , not a whole lot going on with those arrows but since you're hunting plywood who cares

[JimB]

The heavier arrow has about 9% more momentum so theoretically it should penetrate better,if the heads are identical and shafts the same diameter.

Having said that,those are very light setups and I believe neither will penetrate much in 3/4" plywood.I believe any difference,if it can be measured,would be a fraction of an inch.

In this case,I would try a different medium for testing.I prefer minicell foam but insulating foam board should also work.

[ChuckC]

Why not 1" ( 3/4") boards, maybe 1 x 6" which might more closely simulate a bone by cracking open.

Frankly, arrows have been tested in plywood, paper, heck, probably stacked pizzas.  The only place it really matters is in chest cavity.

Almost any reasonable arrow flying straight when the hit takes place, and leading with a sharp broadhead suitable for the arrow, will penetrate a deer's chest enough to kill it.  

Even a 300 grain arrow, which is about half of what I use for deer.  Use what you want.  Its been done before.

Once again, it appears that we are looking for the least amount of everything needed, instead of the most.
ChuckC

[monterey]

It's going to be the heavy arrow at all distances.  Very close shots could be a toss up depending on the quality of the arrow flight.

I think FOC could be a factor, but neither arrow is heavy enough to be a major factor.

[Nativestranger]

Top arrow 300 grains bottom arrow 400 grains.
   
     

Tested 3 sets. Results are quite consistent everytime. The 300 grains arrow always penetrate about 1/4" more. There are 2 layers of plywood. 1/2" in front and slightly thinner one behind. The lighter arrow will always just punch through the second layer. (Point just visible from the back.) While the heavier one makes a small dimple on the second layer. The picture above shows the penetration on the first 1/2" layer. (Second layer removed)

[Nativestranger]

Tests done at 10 yards. By now I think some of you would have guessed the arrows are shot out of 2 different bows. (It's physically impossible to shoot a lighter arrow with higher KE out of the same bow) I repeated the test by shooting the 2 arrows from the same bow and both arrows penetrate exactly the same every time.

[TSHOOTER]

Originally posted by JohnV:
Neither.  Both setups are generating little kinetic energy and momentum.  I would not want to use either setup for big game animals.

This...

[Orion]

Even though the arrows are the same diameter, with a 100 grain difference, one is flying better out of your bow than the other.  I'd guess the 300 grain arrow is. Of course, the same weight head gives the lighter arrow more FOC, which also works to increase penetration.  

In short, difficult to know what factor(s) account for the greater penetration, but weight is only one of them.      

[Nativestranger]

The 400 grain arrow has perfect flight. 300 grain arrow is weak as it showed nock left when sticking in the board. I will continue to test with a broadhead if I can get my hands on some better medium. Maybe some thick ribcage from the market. But for now it seems KE is needed for penetration at short hunting distances.

[Bladepeek]

I will predict that you will see more penetration from the heavier arrow when you switch to broadheads, but will be interested in seeing what you come up with.

[LBR]

Check on the dangerous game forum, and/or with people and PH's who hunt and guide for animals like Asiatic water buffalo, Cape buffalo, etc.

Nothing like experience shooting the real deal.

[Michael Arnette]

Good testing! Those are pretty low energy setups though