Ok so I made up some carbon arrows with 200gr heads. and I weighed the arrow 520 gr overall. I have some Douglas Fir with 160gr heads and weighed 664 grains. So the ? is why would the arrow weighing less penetrate more than the arrow weighing more, they are both shot out of the same bow.
Is it due to the wood arrow flexing more? I assumed the heavy arrow would penetrate better. Please enlighten me.
Who said they would? Might or might not, I suspect the increased velocity of the lighter arrow will make up for the heavier weight and they'll end up pretty equal.
What did it penetrate more into? I have made myself very happy over the years NOT trying to figure out to many things. Some things just are the way they are, and I'm usually fine with that.
All else being equal, a heavier arrow will penetrate deeper than a lighter arrow.
More than likely, your wood arrows, while heavier, are larger in diameter, inhibiting penetration.
The wood arrows are likely much rougher on the outer surface, further inhibiting penetration.
Also, the more perfectly the arrow is on it`s axis will yield much greater penetration.
Lots of variables involved with arrows, but if all variables are removed, heavy wins, every time.
Diameter,friction on the shaft surface,target density all play into penetration on a target. My money is on either arrow would completely pass thru a deer sized animal with a good hit.
They were both shot into the same foam target(yoga block type tight foam) And I guess there are to many variables to consider. Just thought Heavy was better.
Personally I'd go with the heavier shaft. I'm wood arrow prejudice though. Heavier will make for a quieter bow but both will blow they game.
On a live animal you probably won't see the difference. Blood makes a great lube for arrows, that coupled with a good broadhead will open up a big hole.
Many variables,one more also could be the distance of the shot. The wood shaft take more time to regain it's straitness.(the S shape after leaving the bow)
The diameter difference between a carbon and a wood arrow is the main difference in penetration in a foam target as the target material is clamping down on the arrow as it enters. The finish ona wood arrow will also impead penetration in foam. Try shooting 2 carbons of different wieght (assuming tuned to bow) into the same target.
I also bet that 200 grain point on the carbon is a larger diameter than the shaft so the most friction is only on the point.
Eric
Your test is only relative to the difference in arrow construction, material being shot into, and the distance from which your shooting.
Penetration of an arrow into foam and into an animal are two entirely different things. As dnovo mentioned, foam stops the arrow by friction against the shaft, whereas an animal stops the arrow when it can no longer cut it's way through tissue.
A thick bladed broadhead will not penetrate foam as well as a thin bladed broadhead because of friction on the blades. A flat steel blunt will often outpenetrate about any head in hard foam - especially if it's slightly larger in diameter than the shaft.
Think of pulling an arrow from a foam target - if you lubricate your arrows they come out easier - also go in easier. Penetration in foam only tells you how well that combination penetrates foam and doesn't have a lot of coorelation to a broadhead penetrating an animal.
I'm not that all seasoned in trad shooting, but a good deal of engineering got me by pretty well.
My bet is on lighter arrows.
Don't shoot me on this, but this is what I reasoned.
Force for penetration is directly affected by arrow speed and mass. Speed is more significant than weight due to arrow weight being too small to cause drastic changes.
You might also want to consider how far and how flat it shoots.
The angle of entry plays quite a fair bit. Lighter points and you might enter with your arrow head a little too high for good penetration.
Just my 2 cents.
It's been said but friction is the "braking" mechanism.This will be affected by shaft diameter and finish.It can also be affected by temperature of the foam if you happen to shoot each type arrow on a different day.
You can check it yourself by shooting different weights of the same diameter and type shaft.
I've tested a bunch of carbons of same diameter but different weights and the weight always trumped the speed.
They both will and have killed animals. I wouldn't spend too much time on this one. Go shoot and have fun!