Something that hasn't recieved as much attention in this thread as use of handguns in self defense, is handgun hunting or wilderness survival in a light package. If your goal is to hunt with your hangun, or use it as a survival weapon, a revolver is generally far more effective and versatile than a semi-auto, simply because of the much wider range of loadings and bullet types available in the same caliber, without any effect on reliability(unless you are using handloads that far exceeds the SAAMI-specifications of course).
In a .357 magnum revolver for example, one can use everything from whimpy loadings with light bullets in .38 special, all the way up to very powerfull and heavy .357 loadings meant for black bear defense(think
Buffalo Bore), which far surpasses most rounds available for semi autos. If you go up to heavier calibers like .44mag., you can fire anything from light .44 specials to hot loaded .44magnums(where certain ammo gives you comparable muzzle energy from a 6inch. revolver as you get from a 14.5 inch M4 carbine firing 5.56NATO ammo.
Source.) Then you have the even more powerfull .454 casull which exeeds most common millitary service rifles(e.g. 5.56mm Nato, 7.62x39) muzzle energies, while still being capable of also shooting light .45 LC loadings if needed, even from the same cylinder if one wish to do so.
And then you have beasts such as the .500 S&W revolvers, with possible muzzle energies that even surpassed 7.62NATO muzzle energies from a service rifle. Hell, there is even revolvers in .45-70 i you really love recoil and blast. The largest semi auto handgun caliber I'm aware of is the .50 AE from the MR Desert Eagle, which isn't exactly known for reliability, and where the heaviest loads are just comparable to the heaviest .44magnums in power, and this from a somewhat unreliable pistol that isn't capable of shooting lighter loads, as these wouldn't cycle the mechanism., and which has comparable ammo capacity as revolvers.
And if you go the other way, a .22lr revolver is capable of reliably firing anything from .22short, .22long, .22lr and .22 shotshells(ratshot & snakeshot) from the same cylinder reliably, if wanted. Good luck doing anything like that with a semi auto.
Another factor to consider is that revolver ammo is generally loaded to a higher pressure than semi auto pistol ammo, so shooting the samme revolver ammo from a rifle, generally gives you a much bigger rise in velocity/energy than shooting semi auto pistol ammo from a rifle. Pairing a .357 revolver with a 18inch Marlin 1894c lever gun in the same caliber, for example, gives a drastic rise in energy output(comparable to a similary length 5.56 Nato rifle at the muzzle.
Source.), higher ammo capacity, and longer effective distance than a handgun, while still using the same ammunition, easing logistics considerably. A 9mm or .45 acp carbine gives you nowhere near the same rise in energy/velocity over a similarly chambered handgun.
So while one can argue that the semi auto pistol is better for self defense because of a generally higher ammo capacity and faster reloads, there are other areas in which the the revolver have some very clear advantages.
