First developed by Jeff Cooper in 1983, the 10mm Auto is a semi-automatic pistol cartridge. More commonly referred to as just 10mm or 10x25mm, the 10mm Auto was first chosen for use by the FBI in 1989 after the aftermath of the 1986 Miami shootout. Designed to be a medium-velocity pistol cartridge, the 10mm round boasted considerably better external ballistics, such as a larger range and a flatter trajectory, and a greater stopping power than the 9x19mm Parabellum.
