10mm Auto

The 10mm Auto is a powerful semi-automatic pistol cartridge first developed by American Jeff Cooper and introduced in 1983 with the Bren Ten pistol. Although it was selected for service by the Federal Bureau of Investigation in 1989 from the aftermath of the 1986 FBI Miami shootout, the cartridge was later decommissioned (except by the Hostage Rescue Team and Special Weapons and Tactics Teams) after their Firearms Training Unit eventually concluded that its recoil was excessive in terms of training for average agents' and police officers' competency of use and qualification, and that the pistols chambered for the cartridge were too large for some small-handed individuals. These issues led to the creation and following replacement to a shorter version of the 10mm that exists today as the .40 S&W, and while the 10mm never attained the mainstream success of this compact variant, there is still an enthusiastic group of supporters and users.