The .38 S&W is a revolver cartridge developed by Smith & Wesson in 1877. It should not be confused with the .38 S&W Special cartridge which has different case dimensions and a different caliber bullet. Colt also chambered revolvers for the cartridge which they called the .38 Colt New Police - the principal difference being that the Colt rounds where flat nosed, while the S&W used a 148 grain (9.6 g) rounded nose lead bullet.