The .38 Special was the standard service cartridge for the majority of United States police departments from the 1920s to the 1990s. It was also a common sidearm cartridge used by United States military personnel in World War I, World War II, the Korean War, and the Vietnam War. In other parts of the world, it is known by its metric designation of 9×29.5mmR or 9.1×29mmR.
Known for its accuracy and manageable recoil, the .38 Special remains one of the most popular revolver cartridges in the world more than a century after its introduction. It is used recreationally for target shooting, formal target competition, personal defense, and small-game hunting.