In 1985, the U.S. Army took a huge step backwards when it summarily dumped the 45 ACP in favor of the underpowered 9mm Luger cartridge (a.k.a. 9mm Parabellum). Irony: The 9mm is not quite as powerful as the 38 Long Colt cartridge which was replaced by the 45 ACP about 75 years earlier.(Italics in original)
Hm. Let's consult our handy Big Book o' Bullets*, shall we?
- .38 Long Colt: 150gr bullet @ 770 fps = 195 ft/lbs
- 9x19 M882: 124gr bullet @ 1299 fps = 465 ft/bs
No telling how many people caught a case of the derpes from reading that and blithely went off repeating "9mm isn't even as powerful as .38 Long Colt!" around the water cooler.
*I am tickled to discover that the ultimate in gun nerd bathroom reading material is now available in Kindle format.