357 sig

Question
do you know anything about this caliber? compaired to a .40 s&w or a .45acp?

Answer
Charles,

The .357 SIG is actually a .355 or 9mm projectile, housed in a .40 S&W case that has been necked down.

Before the .357 SIG, no 9mm was commercially succesful except the 9x19 (=9mm Luger, 9mm NATO, which has been around since 1908).

SIG Sauer realized it would be the kiss of death from an advertising standpoint to call it a 9mm (which is in fact what it is), so they sought to replicate the external and terminal ballistics of the famed .357 Magnum and named their new cartridge the .357 SIG.

Several state police agencies use the cartridge because of superior penetration through objects.  In my opinion, it is a very specialized cartridge.

One of the real-world problems of the 9mm is that it tends to overpenetrate.  To then take that same projectile and drive it at velocities of several hundred feet faster does not make a lot of sense to me for a self-defense cartridge.

Because it is a bottle-necked catridge, ammuntion is expensive compared to other catridges.

Although data is constantly changing, right now the .40 S&W in a 155 grain bullet configuration is the king of incapacitation.  It seems to be the "magic bullet" in regard to size, weight and speed to do what a defensive cartridge should do.

The .45 230, even in ball configuration is only slightly behind the .40 in the statistics, and may be superior if the .40 fails to expand.

I personally have no use for the .357 SIG, but be advised that if you get a gun chambered in .357 SIG, you can convert it to .40 with nothing other than a barrel change.  Breech face, extractor, magazines for the two calibers should be identical.