I understand speed and energy and all that but experience has shown me that my ol 45-70 knocks em down and dead. My 300 win mag does the same. My 6mm also. So it goes with all my cal. I just see them getting hit harder with that ol 45-70. Only time I knocked a deer off it feet was with my 44 rem mag handgun with 240gr cast going about 1600fps.

Seems if you shoot through an animal with a fast bullet you are wasting some of that energy on the hillside. Just my experience.