Oh, no! Don't tell me a .45 is no better than a 9mm?
On a more serious note, Fairbairn & Sikes discussed this in their book. He said that the more he learned about the subject (stopping power, or whatever he called it), the less certain he was about it, which is certainly refreshingly honest. Others seem to be just the opposite and are positively dogmatic about it, or at least they are in what they write. Unfortunately, some of them have something to sell in the meantime.
Nobody ever mentions how small a target a finger is, either.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.