25 Auto Ammo
The .25 ACP (Automatic Colt Pistol) (6.35x16mmSR) centerfire pistol cartridge is a semi-rimmed, straight-walled pistol cartridge introduced by John Browning in 1905 alongside the Fabrique Nationale M1905 pistol.
The cartridge was designed by John Browning for early blowback pistols that lacked a breech locking mechanism. The cartridge was designed to duplicate the performance of a .22 Long Rifle cartridge, when fired from a 2" barrel. The .25 caliber was the smallest case Browning could use, and utilize primer pocket, and sufficient rim.