Even in cases in which the entire energy of a bullet is expended within a target, there is nothing like the effect we would expect from, say, 147 ft/lb of energy in a 1-pound target. i actually once watched an Army sergeant catch 230 grain .45 ACP GI Hardball bullets fired from 15' into a " catcher' s mit" made of Kevlar that he was wearing on his right hand! This thing was just about the size of a baseball catcher' s mit, but I have no idea how many layers of bullet-stopping and shock-absorbing material it contained. When the bullet hit, his hand was shoved back with about the same violence and about as far as the pistol moved the firer' s hand. No penetration into the glove at all! Then the guy would open his hand, palm-up, and hold the caught bullet out for all to observe. When it impacted, the bullet was carrying over 300 ft/lb of kinetic energy, but there was no obvious commensurate effect on the guy' s hand/arm!! 300 foot/pounds of REAL energy?? I don' t think so!!