What is the difference between a 357 sig ans a 357 mag?

I know this is a silly question, but i am curious and i do not know.

.357 Mag = rimmed, straight case for revolvers, originally.

.357 Sig = rimless, bottlenecked (base of case larger than neck) for semi-autos. Idea being to approach .357 Mag ballistics in a semi-auto handgun.

Dimensionally, or performance wise? In small to medium size guns, the .357 SIG will pretty much duplicate the .357 Magnum. When strong revolvers enter the mix however (Ruger Blackhawks, 353s, N-frames, etc), the .357 Magnum can be loaded to easily outperform the SIG.

Lee Martin
www.singleactions.com

The SIG round was deveoloped to get .357 magnum performance with the 125 gr. bullet out of a semi-auto pistol. To this end, with this bullet weight the SIG round works very well. However, with heavier bullets the SIG round is not as good a performer. The .357 Mag. is a much more versitle round and a much better hunting round. For a CCW, while I favor a .45 ACP, there are no flies on the .357 SIG and you can carry considerably more rounds of .357 SIG in a semi than you can carry .357 Mag in a revolver.

Try this....

http://shootersforum.com/showthread.htm?t=6620