[AGE]

Guys,

Energy and momentum discussions can go on a long time. The above discussions have left off a few things. If a bullet hits a pendulum (or cadaver) and stops in the body--the initial momentum of the bullet equals the momentum of the body (and bullet) just after impact. If the bullet stays in the body the bullet mass is just added to the body mass. If the bullet passes through the body then the bullet velocity (after penetration) enters the picture.

Similarly, there are a lot of energy terms to account for: initial bullet energy, final body and bullet energy, tissue and bullet damage, heat released, etc. etc. This can go on a long time, but the bullet that does the most damage is likely to be the most effective. 9 mm damage may approach .45 damage except in the case of the military which uses only full metal jacketed bullets. 9 mm FMJ bullets slide through flesh with a lot less damage than .45 FMJ bullets. Make mine a .45 (or .44).