VH>Be warned, however, that kenetic energy is not the end-all, be-all of
VH>stopping power.

SB>Specifically? You mean overpenetration (much of the KE exits),
SB>dissipation as heat (both projectile and target) in case of
SB>really high velocity, dumping the KE in a noncritical area, or
SB>something incomprehensible like that formula that considered
SB>the product of momentum and cross-sectional area the measure of
SB>stopping power? (In that case, forget guns; toss a bowling ball.)

VH>There is no "formula" that will predict bullet performance -- kenetic
VH>energy, while scientifically sound (derived by Newton, from his laws of
VH>motion) doesn't tell us how the bullet will perform.

VH>As an example, a .223 (5.56X45 NATO) round has more kenetic energy than
VH>a heavy .45 Colt load.  Yet the .45 Colt would be a more reliable
VH>"stopper" in a fight.

So, is it a matter of where (how deep and over what cross-sectional
area) the energy is delivered? Aren't NATO bullets clad specifically
to minimize expansion, so tend to overpenetrate?
---
  "Taking a long view of history, we may say that anyone who lays down his
  arms deserves whatever he gets." - Jeff Cooper, commentaries, vol.7, no.8