ORIGINAL: bow_hunter44
However, all things being equal, two projectiles, one with a greater mass strike a target with the same velocity. The lighter projectile will almost certainly have a greater KE (after all, velocity in the formula for kinetic energy is squared) when it reaches the target, but the more massive arrow will almost certainly have a greater momentum (due it its relatively large mass).
If they are going the same speed the heavier arrow will have both more KE and more momentum.
I think that you mis-wrote this as I agree with everything else you posted. I've just been reading reports of Dr Ashby's research and am climbing on the heavy arrow bandwagon.
If I interpret the recent article in Traditional Bowhunter magazine, my 60 # Justice @ 26" DLshooting a 682 grain arrow will penetrate a water bufalo's ribs on one side, but not the other. However, the same bow with a 384 grain arrow will not penetrate ribs, even though it's going about 50 fps faster.
I have a little more testing of my own gear before completely I buy into this. But Ashby's research is pretty compelling.
note: the article's formula's seemed to be off by a factor of 10. My bow may be shooting 17 foot pounds, but it is definitely not shooting 170 foot pounds.