10 mm Auto

The 10mm Auto is a pistol cartridge developed by Jeff Cooper and introduced in 1983 by the ammunition manufacturer, Norma. It was originally designed as a high-performance cartridge for the FBI, which sought a round that would offer improved penetration and stopping power over the 9mm Luger.

The 10mm Auto uses a rimless, straight-walled case with a bullet diameter of 10.16mm (0.400 inches) and a maximum case length of 25.4mm (1.00 inch). It typically fires a 180-grain bullet at a muzzle velocity of around 1,200 feet per second, delivering high energy and good accuracy at medium to long ranges.

Despite its promising performance, the 10mm Auto struggled to gain widespread popularity in its early years, as many shooters found the recoil too harsh and the ammunition too expensive. However, in recent years, the cartridge has enjoyed a resurgence in popularity, with many shooters and law enforcement agencies turning to the 10mm for its excellent performance in both self-defense and hunting applications.