Full-Size 10mm Pistols from SIG, Glock, and Rock Island Arsenal
The Glock was the softest shooting, and the SIG was refined, but the RIA was a real tackdriver when firing this high-performance round. For self-defense or hunting, each may have a role for you.
The 10mm Auto cartridge seems to be going through a renaissance. There is new ammunition being manufactured in velocities the 10mm was intended for, like in the newer SIG Elite Performance ammo, and firearms manufacturers such as Glock and SIG have offered new pistols chambered in the round, the G40 Gen4 MOS and P220-10, respectively. We wanted to take a look at the 10mm in a full-size pistol that we could easily open-carry on the back 40 or concealed under a jacket or coat for in town. Since there are numerous examples of 10mm pistols to test, we also wanted to see if a different platform favored the big-bore caliber.
As we tested, we gained renewed respect for the 10mm round. Some testers even thought the round may be a liability in a self-defense situation due overpenetration. If we were in a crowded mall and were able to get solid center-of-mass hits on an attacker, we wondered whether certain loads would overpenetrate and hit a bystander. We do think it is a good round to punch through vehicles with and to stop big bears, and we also feel it is an excellent hunting cartridge if kept to bow-hunting distances on feral swine, whitetails, and small black bears. Around bystanders, we would most likely stick with the 10mm Lite or 10mm FBI loads if we carried the 10mm concealed.
The 10mm Auto creates a maximum pressure in the range of 37,500 psi. Compare that to the 45 ACP, which has about 21,000 psi with 230-grain ball ammo. The round was the brainchild of Jeff Cooper and a few like-minded individuals who wanted better terminal ballistics than the venerable 45 ACP could produce. The 10mm Auto exceeds 357 Magnum power and is very close to that of the 41 Magnum. The 10mm Auto is a brute of a round with the type of recoil you would expect from a magnum revolver. The mythical Bren Ten was one of the first semi-automatic pistols chambered in the round. The pistol never really lived up to its expectations due to magazine difficulties and the 10mm Auto thoroughly trouncing the Bren Ten’s mechanism. The 10mm Auto has such a fast-moving bullet that it tends wreak havoc with the pistol’s recoil mechanism. Colt first chambered its 1911 Series 80 in the cartridge in 1987, and it caused receivers to crack where the slide stop fits into the receiver. A relief cut was made by Colt to fix the situation, and the company’s pistols in 10mm ran fine thereafter. When the FBI adopted the round after the Miami-Dade shoot out in 1986 due to agents’ underperforming handgun cartridges, the Bureau soon realized agents could not or had a hard time handling the recoil of the 10mm Auto. The Bureau had adopted the cartridge first, then adopted the S&W Model 1076, which was purpose-built for the round. The FBI’s solution was to load the 10mm light, which made it more tolerable to agents. The 10mm loads became known as 10mm Lite or 10mm FBI. We all know the light 10mm load is nothing but a 40 S&W in a longer case. The 10mm Auto produces about 300 foot-pounds more energy than the 40 S&W when the 10mm Auto is loaded to its standard velocity, and it’s even hotter with niche ammo like that from Buffalo Bore. The 40 S&W changed the way law enforcement looked at cartridges, and the 10mm Auto might have been forgotten if it were not for some diehard fans — one of whom is on the Gun Tests staff.
Our shooters chose three very popular platforms to test the 10mm Auto: a 1911 design from Rock Island Arsenal (RIA), the SIG P220 model, which custom gunsmiths have been converting to 10mm for years, and the large Glock frame, which has been chambered in 10mm since 1991. All of these pistols in other calibers, namely 45 ACP, have received high grades in the past from us, so our expectation was these pistols would perform, and they did. All the pistols ran exceptionally well, with no malfunctions or jams. That says a lot because some 10mm Auto pistols are finicky because factory ammo is loaded light, standard, and heavy. We used an assortment of ammo; two light loads from Federal and two standard 10mm Auto loads from SIG in the Elite Performance Ammunition line, that are much faster than the Federal’s load. The Federal loads consisted of American Eagle 180-grain FMJs which clocked slightly over 1000 fps, and Personal Protection 180-grain Hydra-Shok JHPs, which had an average muzzle velocity of slightly under 1000 fps. The SIG ammo averaged well over 1200 fps, except for the V-Crown 180-grain JHP in the Glock. The Glock showed lower velocity across the board with all the ammos compared to the SIG and RIA. Note the Glock barrel is also half an inch shorter than the RIA and SIG barrels.