I do believe true knock down power does exist... but we have not reached it yet. The 1st deer I ever shot with a rifle was a 81 lb. Spike at about 100 yards. I shot him with a 220 gr. slug out of a .30-06. He fell as if struck by lighting... dead before he hit the ground. But I did not knock him off his feet. What confuses me is the influence of frontal diameter. According to Garret's a SUPER BROAD MELPAT will penetrate better than sleek spitzer. It would seem to me that a Broad Frontal Area would not penetrate nearly as well, but would have a more dramatic impact. It would be possible to knock an animal off it's feet but wouldn't it require something like a 120mm bullet somewhat resembling a coffee can in shape? Please Clarify!

You have your physics correct ,but may not be thinking of the situation correctly.If you wieghed 100lbs and were hit with the recoil of a 300 ultra mag unexpectantly you would be headed for the ground,and if you happened to be killed instantly it would be very dramatic, possibly flipping you.

The ability to physically move an object with a bullet is MOMEMTUM, not kinetic energy. Momentum is simply velocity times bullet weight in pounds. A 500 gr Lott at 2450 fps has the same momentum as a 175 pound object traveling 1 foot per second.