If you absolutely, positively need something to get dead in an extreme hurry, then the 10mm is for you.
Originally designed by pistol legend Jeff Cooper in 1983, the 10mm auto strove to provide better external ballistics than the .45 ACP round, while also boasting greater stopping power than 9mm Parabellum. Recognizing the merit of such a cartridge, Bornaus & Dixon Enterprises, the owners of firearms manufacturer Bren, contracted Swedish ammunition manufacturer FFV Norma AB (now known as Norma Precision) to further improve Cooper’s design. The resulting cartridge was even more powerful than Cooper had envisioned.
Debuting in the huge Bren Ten pistol, the 10mm instantly earned a reputation for being one of the most powerful cartridges for use in semi-automatic pistol. With bullet weights between 135 and 200 grains, and muzzle velocities from 1,600 to 1,300 feet per second, the 10mm usually delivers between 700 and 750 foot-pounds of energy to the target. For comparison’s sake, that outstrips most .357 Magnum loads by roughly 50 foot-pounds!
In fact the 10mm proved so powerful that it actually killed its own maker; Bren. Due to a staggering volume of difficulties encountered by the storied firearms maker in trying to bring the Bren Ten to market Bren was forced to declare bankruptcy just three years after launching the pistol. Quality issues arose due to the rushed production schedule, pistols were shipped without magazines due to additional production delays, and it all happened at a price that was relatively high compared to most other pistols of the day; $500. And since the Bren Ten was the only gun chambered in 10mm at the time, it looked like this powerhouse of a cartridge’s story might have ended there. But in an unexpected twist of fate, Colt opted to take their much beloved 1911 design, and adapt it for use with 10mm and the Colt Delta Elite was born.
But even more crucial to the 10mm’s story was the 1986 Miami FBI Shootout. Involving two serial bank robbers by the name of William Matix and Michael Platt, and eight FBI officers, the shootout led to the deaths of both perpetrators as well as two FBI agents. This caused a significant reconsideration of FBI tactics and weaponry, as both Matix and Platt were shot 6 and 12 times respectively before succumbing to their wounds, which allowed Matix to kill two agents with his Mini-14 rifle beforehand.
Reaching the unavoidable conclusion that the issued .38 Special +P rounds did not perform to a standard required by the FBI, the Bureau adopted 10mm for a brief time, ultimately selecting the big and heavy Smith and Wesson 1076. However, it would be a shortlived victory for 10mm, as the FBI soon decommissioned the round for general field use because “the recoil that was excessive in terms of training for average agent/police officer competency of use and qualification, and the pistols chambered for the caliber were too large for some small-handed individuals.” This determination would eventually lead to the creation of a less powerful shortened 10mm that would become known as the .40 Smith & Wesson… and it’s subsequent nickname of “.40 Short and Wimpy.”
But while the 10mm proved too much for widespread FBI use (although it remains in use with the FBI’s Special Weapons and Tactics and Hostage Rescue Teams), the determination that it was essentially too powerful for the Fibbies simply added to the mystique that surrounded the cartridge on the civilian market. And although it’s still a relatively uncommon calibre due to both availability, practicality (especially here in Canada), and cost, it has become dramatically more popular as of late, with most large pistol manufacturers now offering at least one or two pistols chambered in the round.