As a follow-up to my CAN THE .40 SMITH AND WESSON SURVIVE? article, I thought that I would touch on some thoughts about the 10mm cartridge.

Imagine, if you will, a 185-grain bullet in .45 caliber traveling at 995 fps. That is not beyond comprehension, as it is the rating of the Sig Sauer V-Crown .45 ACP 185-grain JHP cartridge. Now, consider the Sig-Sauer 180-grain JHP in 10mm traveling at a speed of 1,250 feet per second or the Buffalo Bore 180-grain JHC at 1,399 feet per second out of a 5” barrel. Neither of the rounds are beyond the comprehension of man.

The Sig Sauer 230-grain JHP cartridge in .45 ACP can attain a speed of 830 feet per second (this is my normal self-defense carry cartridge). The same weight bullet in 10mm, as manufactured by Double Tap in a hardcast configuration, is rated at 1,120 feet per second out of a 4.6-inch barrel. That is a significant change in velocity for the 230-grain bullet that is enough to warrant “Twilight Zone” thinking. The only other time I have seen figures like these was for the .45 Winchester Magnum 230-grain (15 g) JHP Underwood at 1,600 ft/s (490 m/s) and 1,307 ft.⋅lbs. (1,772 J) of energy.

The 10mm Auto seems to be the new play child of the ballistics community. It was the ‘on’ caliber in the late 1980s and went ‘off’ after the acceptance of the .40 Smith and Wesson for federal duty use but is now back ‘on’ since the .40 Smith and Wesson has been considered ‘second chair’ to the improved 9mm cartridge. The 10mm never went away, it just faded from the scene like a B-list actor. However, improvements to the 10mm Auto is bringing it back again as a viable self-defense and hunting cartridge, especially from and for bears.

Double Tap, an ammunition manufacturer, has a full line of 10mm cartridges from 135-grain to 230-grain. In fact, Double Tap has a 10mm 135-grain JHP over a 95-grain lead ball @ 1,040 feet per second. “This load is VERY accurate and produces two holes on target. The ball hits high every time – less than one inch from the JHP @ 10 yards and 2.5″ from the JHP @ 25 yards that is rated at 1,040 feet per second (553 ft./lbs.) in a Glock G20.” – Source: http://www.doubletapammo.net/index.php?route=product/product&path=303_301&product_id=596.

Underwood is another ammunition manufacture that features a full line-up of 10mm cartridges for defense and hunting. The 10mm Auto 220 Grain Hard Cast Flat Nose is rated at 1,200 feet per second and the 10mm Auto 180-Grain Bonded Jacketed Hollow Point is rated at 1,300 feet per second.

Of course, there are other ammunition manufacturers that are catering to the 10mm fanboys. There are also plenty that hand load the 10mm round to tailor a favorite target or hunting load. Ammunition prices are on the pricey side but seems to be relaxing a bit due to the increased popularity of the cartridge, but they are sure not in a comfortable price range yet for most.

Both ammunition manufacturers also have a complete line of .40 Smith & Wesson (10mm Kürz?) ammunition. The 180-grain JHP, in my mind, would be an excellent self-defense round and the Double Tap .40 S&W 180-grain Nosler JHP running @ 1,100 feet per second (484 ft./lbs.) at the muzzle of a Glock G23 (4.0-inch barrel) is no slouch, although the Double Tap 185-grain JHP can reach 1,200 feet per second from a 5″ 1911, and with a larger bullet diameter. There would be a need to kick the 1911 recoil spring rate up a bit, I would think.

The .357 Magnum (9.1 mm) cartridge can be download to .38 Special, or .38 Special +P (and +P+) ballistics. The same can be said for the .44 Magnum (a 10.9 mm cartridge), which can be downloaded to .44 Special and .44 Special +P. And we do know that the 10mm Auto can be downloaded to .40 Smith & Wesson (10.2 mm) ballistics. So why do we need a 10mm cartridge? Well, apparently it is a popular enough cartridge for many and for many a manufacturer to sink dollars into research and development in order to bring a better cartridge to the marketplace to feed the mechanical marvels that shoot the cartridge for personal amusement or for more serious work like self-defense and hunting.

The 10 mm Auto cartridge is somewhat of an enigma, although its true purpose was revealed to be a medium-velocity pistol cartridge with better external ballistics (i.e., flatter trajectory, greater range) than the .45 ACP and capable of greater stopping power than the 9x19mm Parabellum. The brainchild of firearms expert Lieutenant Colonel John Dean “Jeff” Cooper, the 10 mm went to Hollywood in a failed platform (the Bren 10), but still became an iconic round. You must admit that the Bren 10 was an exotic-looking firearm, although I do believe the L.A.R. Grizzly Win Mag or a Wildey would have made for better theater but they would not have popularized the 10 mm.

The 10mm Auto does not have the minacious presence as the .45 ACP, even though the .45 ACP case is shorter and fatter than the 10mm Auto case.

I will say that the report when firing a 10mm cartridge does get people’s attention. One day while firing the 10mm through the Springfield Armory XDm, the fella next to my booth poked his head around the corner to see what I was shooting. He said that he know that it was something big but he didn’t know what.

Paul Harrell, in his video “Personal Protection: 10mm vs .45 ACP” brings out several factors for consideration, one of which is the ‘Court Defensibility” of the 10mm cartridge versus other cartridges, and he briefly discusses the Harold Fish case (read: Harold Fish v. Arizona).

Now, if you hike or camp in areas where bear activity is known, and if you carry, you will probably carry something that is known not to be friendly to bears; whether it be a .44 Magnum or whatever. Since a 10mm Auto is in the ‘magnum’ vicinity, it would be a good choice to carry, especially when loaded with bear-unfriendly ammunition.

For defensive purposes, where two-legged animals are more of a threat than four-legged, downloaded 10mm ammunition may be more appropriate, such as the 180-grain fodder that was mentioned earlier. And it can be argued that the 180-grain cartridge was the initial choice of the F.B.I. when the 10mm cartridge was decided upon. The cartridge has been marketed for tactical, defensive and hunting use, and is among the very few rimless semi-automatic cartridges that have been legalized for hunting the white-tailed deer within most of the USA states.

Is the 10mm a more powerful cartridge than the .45 ACP? Yes, it is. But so is the 9mm and .40 Smith & Wesson if you consider ‘more powerful’ in terms of maximum case pressure. Statistically, a .45 ACP FMJ can penetrate deeper than a 10mm round in ordinance gelatin, but in doing so does that mean that the cartridge is more powerful than the 10mm? In relation to moving with great speed or force, the 10mm outshines the .45 ACP once again, at a cost in recoil and noise. The recoil and noise is sharp and well-defined, like a marine ‘snapping to’ in front of a superior officer.

As far as ammunition goes, for shooting paper, buy the least expensive 10mm Auto you can find. Typically this will be full metal jacket or jacketed hollow point. Armscor, Sellier & Bellot, and Prvi Partizan (PPU) are good, inexpensive choices.

On the other hand, for self-defense, you want the ammo that expands the best. Do not save pennies on self-defense ammo. In my opinion, anything in 180-grain is good for defensive ammunition.

Doubletap makes some of the best self-defense ammo available today, though Cor-Bon is good as well. Doubletap’s Controlled Expansion ammo is a great choice, as is Cor-Bon’s Glaser.

For hunting, you want the biggest, most penetrating bullet you can find. Buffalo Bore is an excellent choice. They specialize in ammo for use against big game. The 220-grain hardcast flat-nose ammo by Buffalo Bore is enough to take down a bear. They have lighter offerings for deer.


The 10mm is to the .40 Smith & Wesson as the 9mm is to the .380 Auto. All will do the job, but the long will always do it better than the short. I would hate to see the .40 Smith & Wesson go the route of the .380 Auto, as I think that it has potential as a viable self-defense round against two-legged and some four-legged threats. However, the 10mm needs to be a cartridge that can fulfill multiple roles just like the .357 Magnum, the .41 magnum, and the .44 Magnum, and even the .45 Colt. All are effective cartridges I their own right. I think that the 10mm is an excellent round; it just needs to find its place among the others.

The 10mm cartridge has a lot of power; it is very versatile, produces flat shooting performance, is perfect choice for hunting and it can be used for self-defense. With that said, and except for the hunting aspect, the 10mm is not a clear winner over the .45 ACP for self-defense against two legged predators. However, that’s not to say that it is ineffective.

It is not an overstatement to say that in general, the 10mm cartridges have more benefits than the .45 ACP counterparts.

As a result, in the 10mm vs. 45 discussions, 10mm is not a clear winner. And I do not feel that it will ever replace the .45 ACP, or any other cartridge for that matter. The 10mm Auto is simply another choice in cartridges among a vast array of already existing cartridges and of cartridges yet to be introduced.

Lest we forget the .44 Special (.410 in (10.4 mm)) and .44 Magnum for revolvers, I don’t see the 10mm going anywhere, since it runs the gamut of cartridges from .40 S&W (.40 Auto, .40 Short, 10×22mm) to .44 AMP (.44 AutoMag).

The 10mm Auto does belong. We just need to figure out where.


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About Taurian

Taurian is a U.S. Army veteran and former LEO and Defensive Tactics Instructor. Taurian also has over fifty years of experience as a Technical Writer and Training Program Developer. After leaving home at the age of ten without any shoes, Taurian continues on with many years devoted to the keeping and bearing of arms.

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