"I work in a level one trauma center. The most common gunshot wounds we see are multiple hits from a 9mm, 99+ percent of whom survive. The rarest we see,that is, make it to the hospital are those from a .45acp. The last (and only) two that came in over the last year were “code traumas” who were essentially DOA. Neither survived. There is no substitute for shot placement but under less than optimum conditions a heavier bullet of larger caliber will always do a better job as a stopper." Firearms-Related Comment of the Day: .45 vs. 9mm Edition | I think thoughts like this are being rethunk as we sit here and read, since the Arizona shootings and deaths of so many people by a wee bitty 9mm cartridge see it ain't so slight. Yes, bullet placement is the key but lots of holes in flesh will have the same effect.