ORIGINAL: BobCo19-65
I believe I said this not Arthur, I think Arthur shoots heavier arrows than that. When I did this test with MY bow and MY set up it showed I had a maximum efficiency at around 450 grns. Every set up will be slightly different.
And my tests had nothing to do with performance on game. They were simply measuring the amount of penetration (depth) I could get with different arrows in a consistent medium.
Paul, I'm having a little trouble with the quote. Are you saying a bows efficiency isa direct measure of penetration?It definately is part of it. A bows efficiency as I understand is the the bows ability to transmit max energy to the arrow and not loose energy to other things such as vibration, noise, friction, etc.. A
heavier arrow is able to absorb more of the bows energy then a lighter weighted arrow thus making the bow
more efficient.
Bob, the only thing I am saying is that with my particular bow it seemed to perform best with an arrow weight of around 450 grns, irregardless of spine, diameter or type of arrow. I tried several different arrows from 300 to 600 grns. The 400 and 450 grn arrows did the best for me. Once I got to around 500 grn the penitration started to taper off again.
I don't know what it means to be honest. Other than my bow seems to like 450 grn arrows the best. I have noticed when using a ballistics calculator that when arrow weight increases beyond a certain point Ke starts to drop again. Momentum pretty muchs keeps rising, but Ke will start to taper off again. So I can only assume that penitration must have something to do with both Ke and momentum.
Arthur that is a pretty cool device. I hadn't thought of one that swings. I was thinking something along the lines of a set amount of weight on some rollers or bearings. And when the arrow hit it I could measure how far back it would move. I really wasn't looking to gain any hard data as far numbers go, just comparing arrows to each other is all. That looks much more simple to build though. Thanks for the link.
Paul