The 10mm Auto was introduced in 1983 as the cartridge for the Bren Ten semi-auto pistol, made by the now-defunct Dornaus & Dixon Enterprises, Inc., of Huntington Beach, Calif. According to data furnished by Norma, the ammunition is loaded to a mean working pressure of 37,000 psi, with a maximum pressure of 44,400 psi. This is near some rifle loads and makes this a rather hot handgun cartridge. Muzzle velocity is listed as 1200 fps, and energy at the muzzle as 635 ft.-lbs. Gun and cartridge are the creation of Jeff Cooper and associates, who were trying to develop the ideal combat weapon. The 10mm cartridge is a great combat round with good stopping power, particularly with an expanding-type bullet. However, recoil is quite heavy. In the late 1980s, the FBI adopted this cartridge in a slightly reduced loading, along with a matching S&W pistol, as standard issue.
Hornady, Speer, Sierra, and Nosler offer suitable bullets. The 10mm Auto cartridge has been loaded by Federal, Winchester, Remington, CCI, and other U.S. ammunition manufacturers. Actual ballistics are generally about 100 fps slower than early factory claims, so actual 10mm Automatic factory loads do not significantly exceed .45 Automatic +P ballistics.
Editor's Note: This brief is an excerpt from Cartridges of the World.