.38 Super

The .38 Super, also known as .38 Superauto or .38 Super Auto, is a pistol cartridge that fires a 0.356-inch-diameter bullet. The Super was introduced in the late 1920s as a higher pressure loading of the .38 ACP or .38 Auto. The old .38 ACP propelled a 130-grain bullet at 1,050 ft/s. Wikipedia