The .357 Sig round was developed in 1994 by Swiss firearms maker Sig-Sauer as a way to shoot .357 caliber revolver bullets out of an auto-loading pistol. Muzzle velocity for the .357 Sig round is 1,550 ft / sec to 2,410 ft / sec, with an impact energy of 614 ft lbs to 774 ft lbs. The .357 Sig is a fairly specialized round. For the practical range shooter or plinker, this may not be the best choice, due to the fact that ammo of this caliber is somewhat specialized and may be hard to find.