I carried a 6 inch .357 for my first 10 years on the job, usually with the Magnum loading of my choice. I had great instructors at the academy and later training I attended on my own dime, and felt quite comfortable with the revolver, due to the stopping power of the cartridge and the mechanical reliability.

The department then transitioned to autopistols, and we could furnish our own from a fairly broad list. I chose, and still carry, a 1911 with 7 shot mags (have been more reliable, for me, than the 8 shooters). I thought at the time that the 9mm was no better than the .38 Special and I would have much rather stuck with my 6 shot .357 than any 15-18 shot 9mm ever made.

I spent a few years in robbery-homicide after that. Bullet development has given us bullets in all of the fighting handgun rounds that work pretty well. 9mm +P+ isn't too far behind the 125 grain .357 in real world performance.

That said, the most important round you shoot in a gunfight is the first round. Second round is the next most important. In most circumstances, round number 15 is a whole lot less critical.

If you examine police shootings, most of the time when an officer empties a high capacity pistol, it is because he isn't getting any hits, or empties it just because things go so fast. You can easily shoot a .40 Glock dry in under 2 seconds.

For a person who can shoot well, 6 shots of .357 should be more than enough.

For a person who shoots badly, 18 shots of 9mm may not be enough.

I am still trying to find a gunfight where a party needed more rounds after getting 3, 4 or 5 good hits out of the first 6 fired, using a reasonably effective cartridge. People who haven't solved the problem with 6 rounds aren't very likely to solve it with 15 or 20 rounds.

All that said, psychology is a huge factor in conflict. If you know you can shoot your handgun well, because you have in the past, and you know your handgun to be reliable, and you know your cartridge is generally an effective round from the experiences of others, I don't think it really matters what gun you have, revolver or autopistol.

I am happy with my .45 ACP. It is easier to carry all the time than my old 6 inch .357, lighter, flatter, shorter, probably as good (or bad) a stopper. But if I had to go back to a good .357 revolver, especially in uniform, I wouldn't loose much sleep over it. I just don't see any reason to do it.