Personally, I like bigger bullets. Why? Because while it is undoubtedly true that a critical hit with a .380 ACP is equally effective as a critical hit with a .45 ACP, not every hit is going to absolutely be a critical hit. Folks focus too much on immediate incapacitation, regardless of the fact that it isn't assured unless your shot placement is absolutely perfect, and regardless of how well you may be able to hit stationery or otherwise predictably moving targets at fixed distances in the relaxed environment of your shooting range, that doesn't mean that you'll be able to hit with the same precision when facing a moving target who shoots back, not to mention the very real prospect of your own potential demise.
Once again operating under a simple concept, bigger, deeper holes equals faster blood loss, meaning higher potential for incapacitation over time, not to mention a higher probability of psychological stops considering that a more ghastly wound which is pumping blood out more quickly might just be able to convince the attacker that the fight isn't worth continuing.
Speaking of which, firearms chambered in bigger, more powerful cartridges tend to be more intimidating in a gunfight, as obviously a tiny gun that makes more of a load pop with a tiny spark coming out the muzzle just isn't going to leave as much of an impression as a big gun that makes a loud bang or boom followed by an echoing crack with a bright flash or fireball coming out the muzzle.
Yeah, yeah, I know you're not supposed to rely on such things, and I don't, but a potential advantage is a potential advantage, and I'll gladly take any additional chance of stopping a fight. So even if a .357, .40, or .45 isn't any better at immediately incapacitating someone and I can't hit stationery targets at fixed distances in a relaxed environment quite as quickly with them, I'd still prefer to carry one because to me, the possibility of surviving the fight because the larger diameter/deeper wound caused the attacker to bleed out faster, or decide to stop attacking me because the bullet wounds look nastier, are bleeding worse, or he was simply intimidated/disoriented by the louder bang/brighter muzzle flash, then I'm not complaining.
As folks have said, there are many variables in gunfights, so I figure, why not have as many potential variables which may work in my favor at my disposal?
