The official SAAMI name is the 10mm Automatic. The cartridge was the brainchild of Jeff Cooper, who wanted better external ballistics than the venerable .45 ACP provided. Cooper wanted a round with more downrange energy while still using a heavy, big-bore bullet. When the 10mm cartridge debuted in 1983, Norma was the only factory to offer the round and Dornaus & Dixon Enterprises was the only manufacturer of 10mm pistols, specifically, the Bren Ten.
- RELATED STORY: Perfect 10s – 5 Pistols From Glock’s 10mm Family
The Bren Ten was based on the CZ 75 pistol. What the Bren Ten and the 10mm cartridge did was offer a pistol with the power of the .41 Magnum revolver in a pistol the size of a beefed-up CZ 75 with good round capacity. It seemed like a perfect match. Even Colt released the Delta Elite, a 1911 chambered in the 10mm in 1987, but the popularity of the 10mm waned until the disastrous 1989 FBI Miami shootout.
- RELATED STORY: Gun Review – Sig Sauer’s P220 Match Elite 10mm Handgun
Analysis of the shootout revealed that the agents involved were vastly under gunned. The FBI adopted the 10mm in the S&W Model 1076 shorty afterward. But there was a problem. The 10mm was difficult for agents to control. The 10mm Auto is serious firepower with noticeable felt recoil. The solution was to load the 10mm light to reduce felt recoil, which defeated the purpose of the 10mm Auto in the first place. As the story goes, the light 10mm load was more efficient when redesigned as the .40 S&W, which skyrocketed in popularity within LE circles. The 10mm might have become obsolete if it continued its impotent existence, but ammo companies loaded the round as it was intended—to carry full-bore, wrist-cracking power.
- RELATED STORY: TAC Ultra – Rock Island Armory’s 10mm 1911 Pistol
Gun companies continue to offer rugged, well-made pistols to handle the round, and a few devoted shooters experience the 10mm as Cooper intended: a big-bore, hard-hitting round packaged in pistols with sizable capacities. The round is as serious for defense as it is suitable for hunting medium-sized game. All hail the 10mm! Scroll through the gallery above to check out 10 10mm pistols.
FOR MORE INFORMATION
Rock Island Armory