While it’s not exactly a “Big Bore” caliber, 10mm Automatic ammo packs a punch well above its weight class. It performs every bit like a Big Bore magnum, thumping anything unlucky enough to be on the receiving end with great malice.

10mm was originally conceived to be a hot load caliber, created to hit with a disruptive force like the .45 ACP cartridge, albeit with a much flatter trajectory.

10mm auto quickly became the standard duty caliber of the FBI in the 1980s. They adopted the heavy caliber following their infamous and disastrous Miami shootout with .38 caliber revolvers. After an investigation into the shootout, detectives found the dated service weapons failed to incapacitate the suspects, resulting in the death of two agents. Perhaps the only problem with the 10mm cartridge is that it worked and penetrated targets a little too well. The FBI phased it out of standard service almost as quickly as it was introduced due to “excessive recoil.” 

History Of The 10mm Cartridge

The Jeff Cooper designed 10mm round was meant to be a performance cartridge. It’s more powerful than 9mm with improved ballistics over the .45 ACP. In fact, the 10mm is almost ideal for competition match shooting in handguns because it shoots so flat. It hits somewhere in between the .357 Magnum and the .41 Remington Magnum (according to Hornady, a little closer to the .357). However, it has a relatively compact case that can be chambered in a standard-sized pistol without prohibitive redesign or organic design. It has been used widely in easy to find revolvers designed by Smith & Wesson and Ruger.

The Bren Ten Handgun

The cartridge was originally requested for a one-off pistol design, the Bren Ten by Dornaus & Dixon Enterprises, a design that was essentially cloned from the CZ-75. While generally considered a quality firearm, Dornaus & Dixon isn’t exactly a household name. The pistol never really took off beyond a cult following stemming from the pistol’s flashy appearance in the TV show Miami Vice.

After testing and careful consideration, the 10mm round was formally adopted by the FBI in 1990 for use in the Smith & Wesson 1076 semi-automatic pistol. This was short-lived though, as the Glock 22 and 23 were adopted only seven years later in the .40 S&W. It is interesting to note, though, that the FBI still uses H&K MP10 in their special response teams.

10mm Ammo Quick Answer Box:

What’s The Difference? 10mm vs. .45 ACP vs. .40 S&W

While not exactly ‘rare’, 10mm isn’t exactly quite common, either, at least not to the same extent as the .40 S&W and .45 ACP. The selection of firearms chambered in 10mm is limited.

Until this year, Glock was the only manufacturer of a mass-produced 10mm which would be described by most shooters as affordable. Springfield Armory recently raised those stakes by introducing a 10mm striker pistol of their own design, which is priced competitively with the Glock offerings.

Because of the length of the 10mm case and the intense pressure of the caliber, it must be used on existing large-frame handgun platforms. Those firearms have historically been designed to use .45 ACP ammunition.

Most Popular 10mm Gun?

The most popular 10mm guns are in the 1911 style, with a number of manufacturers using it as their standard semi-auto platform.

In the revolver category, Smith & Wesson and Ruger have both produced 10mm wheel guns, and while they are popular in competition shooting, they have not garnered a mass audience.

Still, Glock’s G20 is the reigning champ as a mass-produced 10mm pistol readily available at an attainable price point. As with their .45 ACP models, which the 10mm Glock 20 is based upon, the G20 retails around $50 higher than Glock’s 9mm-based pistols. This is well within reach for most gun owners.

10mm Ammo Ballistics

In terms of raw ballistics, there is not much of a comparison between the respective calibers. Looking over to Hornady, at the XTP ® line of ammunition. The 180gr. XTP ® in 10mm boasts 1,275fps and a pounding 650 ft/lbs of energy at the muzzle. The .40 S&W firing the exact same bullet shows 950 fps and 361 ft/lbs, and a .45 ACP firing a light 185gr. XTP ® shows 970 fps and 386 ft/lbs at the muzzle. The hottest .45 ACP of the line is the +P, 200gr. XTP ® which produces 1,055fps and 494 ft/lbs.

If you step up to the lighter and hotter 155gr. XTP ® in 10mm, you find a blistering 1,410 feet per second with 684 foot pounds of energy. The same bullet in .40 S&W produces just 1,180 feet per second and 479 foot pounds. So, the 10mm offering is 16% faster, but most significantly has 30% more energy with the same projectile. The 180gr bullet in 10mm is 17% faster than the hottest .45 ACP XTP ® available (+P, 200gr), with 24% more energy.

Which Pistol 10mm Pistol Should I Buy? 1911-Style, Or Striker Fired?

Originally, this comparison was between the 1911-style and Glocks, two distinctly different platforms. With the addition of a 10mm to the Springfield Armory XDm lineup, it seems unfair not to include the newcomer. It’s sure to be mass-produced like the Glock and will surely be an affordable option, a characteristic of 10mm pistols which is in short supply.

There is not a right or wrong answer here; it depends on your wants, needs, purpose, and personal preferences. The single-stack 1911 design has a significantly lower capacity than the striker action pistols, with 8+1 to each Glock and Springfield 15+1.

The striker-fired polymer pistols are lighter; the 4.5” Springfield XDm weighs in at 31.2oz to the Ruger SR1911 Targets 40.4oz. But, there are a lot of purists out there who swear by the 1911, especially in the competition shooting world. This could be because of the infinite number of upgrades available to the 1911; where-as a Glock is a Glock is a Glock.

True to form, Glock is the only manufacturer who currently manufactures a 10mm in anything less than full-size, the G29. So the boarish power of the 10mm is also available for the CCL crowd. As you can imagine, the G29 has significant recoil, so proceed at your own risk.   

Best 10mm Ammo Options

Best 10mm Range Training Ammo

Sellier & Bellot 10mm Auto 180 Grain FMJ

This popular Czech Republic ammo shares the same parent company as Magtech, Sellier & Bellot enjoys its good reputation as a quality mid-grade brand. Their 180gr FMJ offering is proof positive that this caliber is a bigtime thumper, regardless of the bullet being pushed. It exits a 5” barrel at 1,230fps with 605 ft/lbs of energy. A simple FMJ target load in 10mm carries enough power to crush bones of large predators in an emergency.

Remington UMC 10mm Auto 180 Grain MC

It’s tough to say exactly how Remington UMC 10mm stacks up to S&B 180gr FMJ, because the UMC ballistic chart states that a 4” barrel was used. That being said, UMC 180 gr ball ammo is nothing to laugh at, with a powerful velocity of 1,150fps and 528 ft/lbs. Limp-wristing this potent 180gr ammo on the range is not advised.

Best 10mm Self-Defense & Duty Ammo

Federal 10mm 180 Grain Hydra-Shok JHP

The Hydra-Shok line of bullets continues to stand the test of time very well. Federal’s made the ammo for just shy of three decades now. Either the trusted Federal brand name sells it, or it sells because shooters know it works exactly as advertised. That being said, the 180gr Hydra-Shok is a JHP, intended to expand to avoid over penetration in close quarters engagement.

It is powered like a comparable .40 S&W round at 1,030 fps and 424 ft/lbs at the muzzle. So why not just go with a .40 S&W? I’d rather have a pistol capable of far more energy, but not always be forced to use it. There are other 10mm bullet weights available, making it a good option to get more out of your proverbial hand cannon.

10mm Hornady Ammo 

Hornady Critical Duty 10mm Auto 175 Grain Flexlock

This has been the author’s CCL load of choice for over six years now, albeit not in the sledgehammer caliber of 10mm. Hornady opts for a less potent offering in their Critical Duty 10mm because let’s face it, the full power 10mm loads are just too hot for most close combat duty situations. If you’re in bear country, supersize that Ten. But biped predators normally aren’t nearly as tough as big, hungry predators in the backcountry.

Critical Duty Flexlock is designed as an effective JHP with a polymer plug in the cavity. This allows it to penetrate light vehicle skin and glass without overly deforming the bullet. This allows shooters to fire through glass and vehicle skins more effectively in life or death situations. The 175 gr load shows 523 ft/lbs at 1,160fps from the muzzle of a 5” barrel.

10mm Power Packing Performance 

The 10mm is a legitimate Big Bore contender in the handgun universe, packing magnum wheel gun performance in a standard size autoloader. Sadly, it’s performance comes at the cost of punishing recoil. It was enough to drive away a prized advocate for the caliber, the FBI.

The round would have been all but dead in the water had superlative shooters not taken notice of its eye-raising ballistics. The availability of Colt’s coveted 10mm Delta Elite pistol, plus surplus S&W service pistols flooding the market kept it afloat until mass-produced models came along. These factors proved to be just enough to keep the caliber from obscurity, although the infamous recoil has kept it from the law enforcement popularity of its stumpy kin, the .40 S&W which became more of a household name.

It’s hard to look at the 10mm and not see all the benefits the caliber offers to the educated shooter. The 10mm offers real magnum performance with nearly three times the capacity of a revolver. You get much quicker reload times and target acquisition, and the light trigger pull of a single action pistol. It’s booming power level can be brought down on par with a hot .40, or scaled up to eclipse the .357 Magnum. However you like it, the Ten is an underappreciated caliber which warrants you to give it at least a second look.