of the .38 ACP. Even though .38 ACP and .38 Super are the same size, it is dangerous to use the more powerful .38 Super ammunition in a firearm intended for .38 ACP, as firearm damage may result. In the interest of safety, American ammunition companies formerly loaded .38 Super ammunition in nickeled cases exclusively. Since 1974, .38 Super cartridges have been marked with the +P markings used for greater pressure loads. Firearms chambered for .38 ACP Notable firearms chambered for this cartridge include: Colt M1900 Colt M1902 Colt M1903 Pocket Hammer Webley-Fosbery Automatic Revolver Webley Automatic Pistol M1911 pistol (civilian market) See also List of handgun cartridges References External links The .38 Super Auto and .38 Auto (.38 ACP) by Chuck Hawks (subscription req) Pistol and rifle cartridges Military cartridges Colt cartridges Weapons and ammunition introduced in 1900