I've enjoyed reading the "my gun choice is bigger / better / faster / meaner than your gun" posts, many of which were clearly written for their amusement value and the certainty that they would provoke more memorable responses. It seems to me that the real question here is how does one choose a defensive carry system wisely?
Here's my take on the subject:
A good choice of a weapon carry system should be a balance of priorities tailored to an individual's likely defensive encounter circumstances, physical abilities, and body build. Here is my personal set of priorities, along with a couple of comments that will likely generate more of the aforementioned memorable responses:
1.
Intensive training with the selected weapon to the point of unconscious competence (ability to reliably perform on demand under stress - "PODUS"). This is
not negotiable regardless of hardware. You have to be able to reliably place all rounds where they will do the most good in poor light, with and without cover, while moving, in a multiple assailant 360 degree environment. If you're not carrying this, whatever else you've got is unlikely to help much in a seriously bad situation.
2.
Adequate caliber for defensive purposes. The point of carrying a defensive weapon is to be able to stop a threat with reasonable reliability. Although it's fun to experiment with various exotic loadings, most folks who have seen a significant number of shootings up close and personal agree on two things, given good bullet placement: Bigger is
generally better (.45ACP or .40S&W). (This is a bit controversial in some quarters

) and a little smaller and lot faster (e.g. 9mm+P+)
may work just as well
if bullet expansion occurs. This doesn't happen reliably enough to make a lot of folks comfortable, but when it does, the results are quite satisfactory. The.357 magnums from 4" guns have an excellent stopping history, and .38 / .357 / 9mm in +P hollowpoint loadings are pretty good too.
The bottom line is: You would not be poorly armed with any of them.
Although some consider the .380 viable, I see no point to carrying that round when weapons of the same size are readily available in 9mm. Smaller calibers should be reserved for folks who have an overriding need for an extremely tiny carry package, because the ability to stop threats with one or two rounds (the point of this whole exercise) with reasonable reliability in a short enough time to do you any good is poor. Their best use is in deep concealment backup (secondary) guns.
3.
Recoil tolerance. This is a combination of cartridge, weapon envelope, and physical stature and abilities. Once you've learned grip, stance, sight alignment, and trigger control to the point where you can keep all shots in a 4" circle at about 7 yards with a light recoiling gun (a .22 is ideal), try various combinations of guns and cartridges to find what works for you. I suggest going to a range that rents a wide variety of guns and starting with big gun / small defensive cartridge (e.g, full size Springfield XD in 9mm, and 4" all steel .38 Spcl) with self defense ammunition. Work up in cartridge (.40 S&W, .45ACP) to your point of tolerance, and then down in size (compact semiautos and 2" revolvers) until you find the smallest package for the largest caliber you can shoot competently. You can rent a lot of guns before you equal the cost of a single purchase decision that you regret.
This is a good place to start your concealed carry system, and it doesn't matter much if your selection process ended up with a revolver or a semiauto. The ability to deliver consistent vital zone hits with the first few shots is
much more important than the number of shots available before a reload. Without that ability, more rounds won't help.
4.
Complexity. If you're a "learned to shoot on the weekend, loaded the gun, and won't shoot it again for 6 months" person, the revolver will have significant advantages for you because its manual of arms is much simpler than that of the autoloader. If you don't shoot a lot (at least monthly) I suggest you consider that simpler may be better for you. You'll build confidence more easily, there will be fewer things to go wrong, and fewer ways to get into trouble. If you're willing to spend a lot more time learning about weapon function and working on the range, the semiauto will also be a viable choice.
5.
Carry Method. If you follow the selection process in step 3, this step consists of selecting a holster system for your chosen weapon. There are
lots of very fine carry systems available and the selection extends far beyond what you'll find in even a very well stocked gun shop. Talk to instructors and very experienced CHL holders for recommendations. Posting a request for suggested solutions to a given challenge on this forum will quickly get you lots of excellent responses. Women often find that female instructors have insights that are especially valuable in addressing their individual concerns.
This post certainly won't end the revolver vs. semiauto debate, and it's not intended to be a definitive treatise on how to pick a defensive weapon, but I hope it will refocus some attention on what's really important.