Not ONE of these studies takes real world practice and the common citizen into account. A couple controlled rounds into a specific (and single) target. I see no mention of cost. With the same money or less you can practice MUCH more. This will make the shooter more prone to getting that perfect shot and also safer when innocent people are around. 9mm also offers less recoil so that in panic situations when hammer firing you will be more likely to group tighter and quicker. End result is a more controlled burst of rounds on target and less likelihood of any strays harming innocent people nearby. It also doesn't take into account that most people that conceal for protection only carry a single handgun w/o a backup mag. So, again all things being equal, I can carry 17+1rds of 9mm in my Glock to about half that of a 1911. Most people talk about killing a 'bad guy' but what happens when it's 'bad guys'? I've got more rounds which will better allow me to stop or at least wound more bad guys. If a guy approaches you for your wallet with a group of five or six of his buddies and they have knives are you going to hope that you get perfect shots off on all five moving targets under the most intense pressure of your life? Keeping with the same scenario let's pretend for a moment you only wound them. You still think they want your wallet or are they going to use what's left of their ability to get the fuck out of dodge? If there's ANYTHING 18rds of 9mm Ranger SXT can't at least heavily weaken then I'm running the opposite way as fast as 285lbs can go anyway and I'm also pretty sure 13rds of .45 wouldn't have done much more damage either. It just burns me when people go on and on on these internet forums about how 9mm rounds are made of some magical flubber material that bounces off all but the thinnest and most fragile of skins. It's just as capable as killing in the real world in the right hands as the next handgun.

The reality of it is all handgun calibers do is poke holes. Some holes are slightly larger than others but they are still just holes and the more holes you can poke in the area of vital organs w/o endangering innocent people nearby the better you are.

Bottom line is shoot what you're comfortable with and shoot it as much as your funds and time allow. This is the best possible solution to the what caliber debate because placement trumps caliber EVERY time w/o fail.