I (and most anyone I know) don't shoot 185 or lower weighted bullets in .45ACP.
http://www.midwayusa.com/viewproduct/?productnumber=112504&cm_mmc=Froogle-_-Ammunition%20-%20Centerfire%20Handgun%20-%20Self%20Defense-_-PriceCompListing-_-112504
I carry 165 Grain EFMJ in my 3" Colt New Agent, the loads at the link above.
Muzzle Velocity: 1140 fps
Muzzle Energy: 476 ft. lbs.
I'm sure that's out of a 5" BBL, which is why I went with this round for the 3"
:twirl:
Of course in my 5" Springfield I carry 230 Gold Dots.
ETA - After reading the rest of the thread... a few things.
Yes, stopping power is largely a myth. Bullets do crazy, unpredictable things a lot more often than most people think. Anyone who has shot tracers in low light can attest to this. Hyrdo-Static shock, while not reliable at all... is something to take note of. If it can cause damage to soft tissue (vital organs), it will have some effect. It may not be the most important, but it applies at times. Same with fragmentation.
As stated by the Robot, the only guaranteed way to put a bad guy down quick is a Central Nervous System shot... which is HIGHLY unlikely to happen on a two way range. Which is another good reason to have larger capacity magazines, or even extras.
I'm not without my bias, but I prefer to take into account penetration and transferred energy. In my OPINION, the round that penetrates the most while transferring the largest amount of energy possible is the one I would want. Ultimately, for me, it comes down to the gun I'm comfortable with. If used properly, anything with sufficient penetration (taking clothing into account) can and will get the job done if used effectively by the shooter.
This personal choice is why I normally EDC a 3" 1911 with the aforementioned 165gr rounds. I'm more familiar with that firearm than all my others, it's got the highest round count AND the lowest failure rate of all my handguns. Even without sights, I shoot it the most accurately.
A super ninja round wouldn't do me any good out of a gun I couldn't shoot very well. Ultimately, when it comes down to it... pistols are a last chance, spur of the moment tool for protection. They are very poor man stoppers. If I knew I was going to be in a firefight, I would either bring a rifle or not go at all. The rifle I would bring would be one of the accurate ones, with a good rate of fire and magazine capacity. Proper violence of action usually can turn any fight in your favor if used effectively.
At the end of the post, I won't be disappointed if a Tommy Gun or .45 ammo isn't available in New Vegas. I never liked the things anyway. Fun to shoot, but they're too damn heavy. I was hoping for a good precision weapon to use above all else, and hopefully we'll get some. The Anti-Material Rifle and Scoped Varmint Rifle look promising.