by SekiRyu » Mon Feb 14, 2011 11:54 am
I should have clarified in the first place--this is about bullets used by handguns and rifles. Last time I checked, 30mm was used by A-10s in close air support--and they usually don't hit people directly (and the mass is still much less than a human's).
The only way to physically knock someone down is with blunt force trauma with an object that has much more mass than the person (or to hit at a certain tipping point where the person will lose balance). When the projectile penetrates, there is no "energy transfer". Even an object lighter than the projectile, like an empty coke can versus a 7.62x54R, doesn't get knocked anywhere when shot. However a lighter BB which doesn't penetrate will knock the can over (personal experience). Three 30-06 rounds to the chest of a running Chinese soldier didn't stop him in his tracks either (Great Uncle's experience, Korean War).
Anyway, my $.02 on the subject are done.