Not a definitive study but seemed consistent to me. For me it’s the speed weight combo that is important. I like a fast bow so I can shoot an arrow that matches my mental computer that will produce sufficient penetration. If I can get that at a lower draw weight then I shoot more accurately which produces clean kills.
Well here’s what I came up with using 2 very different arrow weights. Both arrows fly true out of my bow. I didn’t calculate the FOC on these but I know that the 708 gr arrow’s would be higher. The 430 gr arrow had a magnus 100 gr 2 blade broadhead and the 708 gr one had a 250 gr grizzly.
I want to do this with a better medium say 1/4″ mds with a foot of foam behind it. This should give greater penetration which would give better numbers to work with. As it is it looks to me that penetration follows momentum pretty close but that’s not unexpected with this crew. The 430 gr arrow is no slouch though. Just happens that the 708 gr @ 160 matches my mental computer.
Weight 708 gr 160 fps 40.26 KE .503 Mo
Weight 430 gr 204 fps 39.75 KE .390 MO
KE increase 708 vs 430 = 1.27%
MO increase 708 vs 430 = 22.56%
Phone book = 1 3/8″
708 gr = 4.0625″ penetration = 300%
430 gr = 3.125″ penetration = 227.3%
Penetration 708 vs 430 = 23.08% increase
