[Smarter Gun]

Personally, I don't think that any of the popular equations adequately describe the phenomenon of, 'bullet stopping power'. Mass and velocity are certainly involved; and, of the two, velocity seems to hold greater significance. The reason I say this is because of the fact that it is obvious to me a 230grn 45acp slug will NOT hit as effectively as any 150grn 30 caliber rifle round – of whatever bullet configuration!

Two real world object lessons come to mind: The first is those films of Russian snipers shooting German soldiers during the Second World War. In the several examples I've seen, all of the Germans went immediately to their knees or face down upon being struck. Personally, I doubt that this would have happened with any single WWII pistol round. The second lesson involves those, 'tumbling' AK-47 rifle rounds used by the Russians in Afghanistan - Even our ballistic experts were impressed with the results!

(Let’s remember that it's not, really, appropriate to include a weapon like a German MP-40 Schmeisser or any other pistol caliber, 'sub-gun' in this discussion.)

These things said, the old axioms continue to ring true: 'Never bring a pistol to a rifle fight!' and, 'Keep firing (your handgun) until the target goes down!' IMO, a pistol - any, 'semi' pistol with a barrel shorter than 12 inches - is an expedient and should be properly regarded by a savvy gunman as primarily a defensive weapon.

Is this opinion perfect? Certainly not! A lot more could be said. I will, however, emphatically state; 'You'll probably survive a lot more gunfights, and live a whole lot longer if you heed this advice – I trust this point to suffice!