The miltary is restricted to using BALL ammunition. With that a given, the 45 is the winner. Big holes better than small holes.
There has NEVER, I repeat NEVER been a single study, test, or any other documentation that shows 45 is any better than 9mm when using the same exact ammo. Compare FMJ vs FMJ or modern HP vs modern HP in 45 vs 9mm and every single one of them shows a tie.
Historically the 1911 and 45 ACP were not particularly well liked during WW-1 through the Korean war. It was only the largely fictional writings of Jeff Cooper that lead to the "legend" of the 1911 and 45 ACP. That and pure nationalism wanting to avoid a gun and caliber used by one of our enemies.
The army wanted to ditch both after WW-2 and go to a hi-cap 9mm.. Their testing at the time showed no difference in performance against humans, but the 9mm outperformed 45 easily in barrier penetration. The 45's were bouncing off steel GI helmets at fairly close ranges while 9mm still penetrated at ranges of over 100 yards.
Going back to the 45 would be a step backwards. Our enemies are starting to use body armor and 45 has always sucked at defeating that. 40 S&W, 357 SIG or 10mm might be a step in the right direction, but the current 9mm is just fine.
Most people don't really want the truth.
They just want constant reassurance that what they believe is the truth.
