The US Military, especially the army and marines are looking at another standard handgun change, and one of the criteria is a .45 caliber (not neccessarily .45ACP though) bullet because they're finding that in Iraq and Afghanistan, against fanatical types who may (or may not) by hopped up on drugs, that the 9mm's they're mostly using just aren't doing the job at putting people down with a couple hits.
Now the reason they went to a smaller caliber from the .45ACP twenty plus years ago was the thinking that the lighter 9mm ammo would be easier for second-line personnel to use (like truck drivers, medics, logistics folks, the support personel basically who wouldn't normally see front line action) and thus more likely to actually hit a target with, as well as enable everyone who are carrying sidearms to carry more ammo for a given weight of gun and ammo.
The IRONY here is that this all happened once before... a century ago. In the late 1800s, the US Army switched its standard sidearm caliber from the .45 to .38 Caliber, for the similar thinking as above, and then they went to war in the phillipines where they went up against fanatical muslim rebels who were using narcotics before they went into battle to give them an "edge" as it were against the infidel americans. And after that war the US Army went back to a .45 caliber weapon, and that eventually became the now famous M1911 autopistol and the .45ACP bullet.
Now CONTRARY to whatever they might try and prove on mythbusters about guns and gun stories (hollywood or otherwise), flukes and oddball shots DO in fact happen. In fact, if you watch the show enough, you quickly realize that the reason they "bust" many myths is because they're using methods not actually present in the myth, or the time period of the myth. In one episode they proved that a whiskey flask or a pocket watch or deck of cards wouldn't stop a bullet in the old west, yet they used a modern replica .45Colt revolver to do it. But there were OTHER calibers back then and they just used the most powerful one they could, and with modern ammunition as well.
Meanwhile, when they were testing a quickdraw myth involving shooting silver half dollars before they hit the ground (drawing, cocking and firing), they did in fact hit the things several times, using a modern replica revolver and authentic replica ammunition (meaning the same types of bullets and powder). A silver half dollar isn't very thick, and being silver, isn't super strong or hard (and the silver pocket watches and whiskey flasks they tested for the earlier myth represented just as much material to shoot thru), yet every shot simply dented the things.
