Based on your reply, I suspect you may be acquainted with Marshall and Sanow and their alleged "database" of one shot stops... if I'm mistaken, then please disregard the next few paragraphs, but if not...
You may be in danger of taking a good deal of flak on this board if you refer to them, or the so-called "one shot stop," too often... their work is dismissed by most serious shooters as not only inaccurate, but fraudulent... although not all agree. Here are a couple of the more prominent criticisms of their methodology and work:
http://www.firearmstactical.com/marshall-sanow-discrepancies.htm
http://www.firearmstactical.com/marshall-sanow-statistical-analysis.htm
http://www.angelfire.com/art/enchanter/terminal.html
Ironically, Googling "Marshall and Sanow" comes up with more criticisms of their work than defenses... many people believe they made up their statistics to sell books and make money from certain ammunition manufacturers.
Anyway, I just say this to warn you of hoping for ANYTHING in a gunfight. As you said yourself, sometimes there are statistical anomalies that cannot be explained. In my opinion, the best defense against these "anomalies" is a very controllable handgun rahter than a particular handgun round. I can shoot my 9mm, 40S&W and 45ACP handguns VERY quickly and accurately, so you don't have to start with .22 and work up. I also don't believe that any one of the three is particularly more effective than the others - they each have their strengths and weaknesses, and as long as I am able to employ them properly, I think that's the key. This means practice, and lot's of it - but I do think it's important to practice shooting as much as a whole mag, reload and that mag too, occasionally, since that MAY be what it takes to stop an attack.
Again, just my $0.02
ETA regarding the 1911, I have found mine to be a reliable firearm, when maintained properly. Any gun can fail, be it a revolver, automatic, or single-shot shotgun. The key, there again, is practice. I've heard of some pretty nasty revolver stoppages - squibs lodging a bullet in the forcing cone / cylinder, primer backing out, gun getting out of timing, etc. that can all put a revolver COMPLETELY out of the fight, whereas most auto stoppages are easily and quickly cleared. After all, tight or not, looking at all the go-fast high-speed low-drag types who use the 1911 as their fighting gun (Delta, Force Recon, FBI HRT, etc.), it can't be THAT prone to failure, or none of the guys who really do shoot their guns at people for a living would use it. Just food for thought.