I once read an artice by Larry D. Jones on elk hunting and he said in his article
if you keep your arrow weight at or above 450 grains for elk you should be fine
reguarding penetration as long as your arrows arrows are flying straight. Kinda
one of those things you read and remember after a long time. I have found this
to be a good rule of thumb. The Best Elk Arrow is one that fly's straight, and one
that has the momentum/weight to get the job done. -IMHO.