The 10mm - Caliber Pistol Cartridge

U.S. Precision Defense In 1983, the late Lt. Col. Jeff Cooper, USMC retired, was working on a pistol and caliber he felt would replace the .45 auto...

The 10mm - Caliber Pistol Cartridge

The 10mm - Caliber Pistol Cartridge

Written by Guest Article / Contributor , in Section Ammunition Reviews

U.S. Precision Defense

In 1983, the late Lt. Col. Jeff Cooper, USMC retired, was working on a pistol and caliber he felt would replace the .45 auto that had served the military and civilians for more than 70 years.

He referred to the caliber as the "Super Forty," and had Domaus and Dixon Incorporated, designing the pistol called the Bren Ten, inspired by the CZ-75, semi-auto pistol.

As often happens, production of the pistol was delayed by several problems and Domaus and Dixon went bankrupt and Cooper had to look for another pistol manufacturer.

Colt agreed to build the pistol on it's successful 1911 platform and the 10 mm was finally being produced. S&W agreed to produce the ammunition for the new semi-auto pistol.

10 mm auto rounds were impressive. A 175-grain bullet left a 5-inch barrel at 1,290 feet per second, and generated 649 foot-pounds. of energy at the muzzle, while a 180 grain bullet left the same five inch barrel at 1300 feet per second, and produced 708 foot pounds of energy at the muzzle.

On April 11, 1986 eight FBI agents in Miami, Florida, got into a shootout with two heavily armed bank robbers. Although the bank robbers were eventually killed, when the dust settled, two of the agents were dead and five were seriously wounded, ending their FBI careers. The incident became known as the "Miami Massacre."

The most incredible thing about the shoot out is that both bank robbers were shot several times, one in the heart, early in the fight by .38 Special rounds, 9 mm rounds and 12 gauge shotgun rounds, but continued to wound and kill seven of the eight FBI agents.

The FBI turned their attention to why the initial bullets that hit the robbers didn't stop the fight. They also asked Colt to supply them with several of their Delta Elite 1911, 10 mm pistols to test.

The FBI Eventually purchased a large order of Smith and Wesson 1076 pistols in 10 mm, and issued them to their agents.

Because the size of the pistols were too large for some of their agents hands and recoil didn't allow fast follow up shots in any but the largest, strongest hands, the FBI reduced the size and power of the 10 mm and called it the Smith and Wesson Forty. The FBI Hostage rescue Team, as well as the FBI Special Weapons and Tactics team are still issued the 10 mm if they prefer one.

A friend of mine who lives on a ranch outside of Lawton, Oklahoma recently emailed me to say that he and his two sons carry 10 mm pistols as their concealed carry choice. He also e-mailed me a picture of himself and the boys with their Colt 1911 Delta Elite 10 mm pistols. He and his boys are big enough to play defensive tackle for an NFL football team, so they aren't particularly intimidated by the caliber.

I can see the 10 mm as a back country pistol, but have never recommended it as a daily concealed carry option because it is a very powerful pistol that can easily over penetrate the target and endanger whoever and what ever is behind the target. It also recoils with 11.4 foot ponds. of energy coming back at the shooter at 18.1 feet per second. That might not sound like a lot of energy compared to most rifles, but you are holding it in your hand rather than bracing it against the shoulder and the pistol only weights about 2 pounds, and the speed of the recoil velocity is more than many of the rifles used for deer and elk hunting. As mentioned above, fast, accurate follow up shots are difficult unless one has large powerful hands and is experienced in controlling the recoil of the 10 mm.

Today, civilians are showing an increased interest in the 10 mm for back country travel, and there are a lot of fine pistols being produced in the caliber. Colt, Kimber, Glock, Sig Saur, Smith and Wesson, and Dan Wesson all produce 10 mm pistols. Many of those manufacturers have opted to build their 10 mm pistols on the old Colt 1911 platform because of it's rugged construction.

The 10 mm is not for everyone. People with small hands will have trouble griping it properly, the recoil is pretty intimidating to many, and ammunition isn't cheap.

As a back country hand gun, I think the 10 mm is an excellent choice if the shooter can comfortably handle it. It has plenty of power and hits hard, while being a little more compact than .357 and 44 magnum revolvers. The Danish arctic unit, the Slaederpatruljen, issues their members Glock 10 mm pistols for defense against polar bears. I'm not sure I would be comfortable having only a 10 mm pistol for use against polar bears, but the Sladerpatruljen seems happy with it as their side arm.

Many owners of the 10 mm bought it to hunt deer size game out to 30 or 40 yards. The cartridge with 175 and 180 grain bullets is certainly capable of hunting deer at that distance. Handgun hunters have always prided themselves on being able to get close to game.

One nice thing about the different manufacturers of 10 mm auto pistols is there isn't any junk that I have run into. They are all well built quality firearms. Just make sure it fits your hand comfortably and that you understand the proper two handed grip, so you won't be intimidated by it's recoil if you decide to get one.

 This Article first appeared on The Idaho Journal 

Smokey Merkley was raised in Idaho and has been hunting since he was 10 years old. He can be contacted at