The .38 Special Ammo, also commonly known as .38 S&W Special (not to be confused with .38 S&W), .38 Smith & Wesson Special, .38 Spl, .38 Spc, (pronounced “thirty-eight special”), or 9x29mmR is a rimmed, centerfire cartridge designed by Smith & Wesson. The .38 Special is most commonly used in revolvers, but also finds use in semi-automatic pistols and carbines.