.45 ACP & 9mm FMJ

The_Chieftain: I think this argument is missing, for a military-themed forum, the most important question. "What effect are you trying to have with your pistol?"   You've been all rabbiting on about terminal ballistics and incapacitation and whatnot. I submit that for the typical grunt, this is irrelevant. The average Joe (not MARSOC elite or whatever) using his sidearm isn't trying to kill or incapacitate anyone. The chances are that the reason that someone like me is using my sidearm is because something has gone seriously wrong, and I'm just trying to make my way back to my tank/get the hell away from wherever I am/get to a bigger gun. I'm shooting for suppressive/psychological effect. Round A may be less effective than round B, but does that really matter to the guy on the receiving end? He hears lots of bangs, and impacts near him, is he going to think to himself "Ah, it's just a 9mm, not a .45, I'll stick my head out, it won't hurt as much if it hits me"? I doubt it. And, put simply, one gets more bangs from a 9mm than from a .45.   So as my sidearms in the military context, I'll take the 9mm over the .45 please.