.357 Sig is "simillar" to performance of a .357 mag ( and with SIG and others ) it's available in a semi-auto vs a revolver weapon. common rounds on .357 SIG are 124 grain at about 1340 FPS or 147 grain at about 1200 fps.
.357 mag a common round is 158 grain at 1375 fps
The .357 mag will hit a little harder in this configuration but the .357 SIG is similar ....
I'm not a big fan of the .357 SIG. You can get the 229's / 226's etc by SIG in .40 S&W with I believe what is the same 12 round magazine as in a .357 SIG and the performance of the .40 S&W is a lot better in terms of stopping power. The .357 SIG ammo is pretty expensive as well - a lot more than 9mm - but not much less, if any, than .40 S&W which is a more popular caliber.
The 357 SIG was designed to get the ballistic equivalent to the so called "best" self defense handgun round,the 125 gr 357 mag revolver round, out of a semi-auto handgun. It comes very close to doing so, the 35 foot pounds of difference at the muzzle is pretty much inconsequential. I know two officers who have used them in the line of duty and they were impressed with them. A couple others who carry it have used it to finish off car hit deer and feel they work better than other calibers they have used. I myself have reservations though they are unfounded so far. It has to do with a bottlenecked cartridge in a revolver. My previous experience with this type of cartridge has been in the S&W 53 in 22 Jet. It is a necked down 357 and is very picky on having clean chambers. If the chambers weren't spotless, the cartridge backed out and froze the cylinder. This experience has left an impression on me that carries over to the SIG round (30 Mauser too). It may be an unreasonable phobia but confidence in one's equipment does play a role in this area. I'm more of a straight walled case kind of guy.
Having shot a 357 Sig in a Sig 226 DAK-R for almost 2 years I have an opinion.It is a shooter and vey accurate at that. The performance in ballistic gel is great. I had been carrying a Sig 226 in 9mm w/ 124gr +P+ Gold Dots. The 357 Sig is a 125gr Gold [email protected] The ballistics of the 2 we carried were just hair splitting in difference. I wanted the 40cal but was told the 357 Sig was our replacement. I have chewed it up and swallowed it so to speak..... We have not had any problems related to ammo/gun, just some faulty factory magazines, limp wrists and dry and/or dirty weapons.
The 357 Sig has a snappy recoil like the 9mm +P+ ammo. No roll like a 40cal or 45ACP.
I have a Beretta 96 40S&W that I bought a 357 Sig barrel for. I like the caliber and the power of the cartridge. The only problem is the recoil of the 357Sig is too severe for the 40 recoil spring, so I took it out and put the 40 barrel back in. I didn't have any problems with the feeding or ejecting at all. It was a fun caliber to shoot, I just wish I had a spring to slow down the slide a little.