This is one of those topics that always ignites controversy.
IF we were restricted to only lead or FMJ bullets, I'd carry a .45, .44 or .38 Spl (the old "FBI" load), but since we have premium bullets, the 9 is as effective as any and better than most.
According to details found at Chuck Hawks
, a 9mm 115 +P Cor-Bon has a "1 shot stop" rating of 91%, whereas a .45ACP 230 grain Hydra-Shok is 94%.
Admittedly, all that is subjective, but it is in line with other data I've read.
I find a 9 easier to carry and don't feel the least bit undergunned with one. I own- and can shoot quite well- a 1911, but it just don't carry well concealed with my build.
My whole point is don't ASSUME a 9 is too weak on the basis of 1 extraordinary case.