10 millimeter ammo

Why The 10mm Isn't Everything It's Cracked Up To Be

Don't get it wrong; the 10mm is a fantastic round in a great many aspects. It's a great balance of power and shootability - more powerful than most other auto rounds, but also with diverse enough loadings for many shooters. However, it's capabilities can get exaggerated.

If you want to carry a 10mm then you definitely should. If you shoot it well.

However, it isn't the be-all, end-all that some people like to think it is.

The FBI Dropped The 10mm For Good Reasons

10 mm ammo

What a lot of people like to point out is that 10mm was used by the FBI for a time as the default caliber in their duty guns. It got better results than any other caliber, including 9x19mm, in the FBI ammo tests of the late 1980s, which more closely mirrored real-world performance than any ballistic testing done by the agency up to that point.

That said, the 10mm didn't last long as the duty round of the Bureau despite all the perceived advantages.


First, some agents had problems shooting the 10mm due to the stout recoil of the original 10mm load. They tried stepping down in power, leading to what is now referred to as the 10mm FBI load or 10mm Lite...for a time.

Shortly thereafter, Smith and Wesson realized that they could trim the case length without sacrificing performance of the reduced power load and the new case length would then fit a 9mm frame, which was handy.

You see, the S&W 1076 and 1026 pistols (chambered in 10mm) were necessarily larger than the 5906 pistol in 9mm, with a wider grip and frame to accommodate the bigger round. This gave a number of agents issues. However, the 5906, chambered in 9x19mm, did not, which the new round could work in. Thus were born the .40 S&W and the S&W 4006 pistol chambered for it, and thus began the career of the .40 as a law enforcement round.

So...not as many shooters can handle 10mm, and it turns out .40 S&W is a capable defense caliber without the punishing recoil or having to use a larger handgun.

And let's also not forget: the Bureau has switched to 9mm. They noticed no benefit in a larger caliber as the terminal performance of modern 9mm ammunition is so good and reliable that the increase in cost, the difficulty for newbie shooters and so on just isn't worth it. Virtually every police department in the nation has done likewise.

Point being that the average civilian has nothing to gain from it in practical terms.

An Autoloading .41 Magnum It Ain't

10mm ammo

What some people like to say about the 10mm is that it's basically a .41 Magnum that fits a semi-auto.

No. It's not.

The typical 10mm load is a 180-grain bullet, much like the .40 S&W. (Typical meaning most bullets you'll find in the typical gun store...if they even carry 10mm.) The typical .41 Magnum (same idea, and likewise good luck at your local gun store) is a 210-grain bullet. Plenty of lighter and heavier of both, to be sure, but those are the run-of-the-mill loadings much like 230-grain .45 ACP, 147-grain 9x19mm, or 180-grain .30-06.

Now, a typical defense load for both would be something like...say...Hornady XTP hollowpoints, for example. The 10mm 180-gr XTP has an average muzzle velocity of 1180 feet per second, generating 556 foot-pounds of muzzle energy. The 210-gr .41 Magnum XTP travels at 1545 fps and generates 1113 foot-pounds of energy.

Granted, you can find much stouter loadings of 10mm by handloading or finding a factory brand that dials the 10mm up a notch, such as Buffalo Bore's 220-gr Hard Cast load (1200 fps, 703 ft-lbs) but the reality is that the 10mm can only rival the lowest end of the spectrum when it comes to .41 Magnum.

If you want serious power, large-bore revolvers reign supreme and there's just nothing you're ever going to be able to do about it.

That said, the 10mm DOES handily equal the .357 Magnum in many loadings. The aforementioned Hornady XTP load in .357 Magnum and a 158-grain bullet - the classic .357 Magnum loading - only nets about 70 fps over the 10mm and roughly equal muzzle energy.

A great defensive cartridge? No doubt. But it isn't quite one of the big boys.

In fairness, 10mm Auto HAS been successfully used to defend against bear attacks, and has been successfully used for handgun hunting. Is any of this to say it has no virtues? No. This is instead to say that unless there's something specific you need a 10mm for, it has fewer upsides than some people claim.

10mm Ammo Is Expensive And Rare

10mm ammunition

Like a number of other handgun calibers that offer better performance than the most popular chamberings, good luck finding 10mm in the local gun store. The big-box stores that deal with guns - Sportsman's Warehouse, Cabela's, Bass Pro, Gander Mountain when they return from bankruptcy - will have some...but not all that much.

You'll also spend a lot in the process.

Remington UMC is a decent brand of hardball for range use. You can find it in nearly any gun store and for multiple calibers. On Midway, a 50-round box of 10mm 180-grain FMJ goes for $35.99, before shipping. The same box of .45 ACP goes for $20.49, before shipping.

Now, there's something to be said for investing in what will save your life. Spend where it matters and you'll never have to worry, or something to that effect; you get the idea. But are the benefits of 10mm so great that it's worth the extra headache and expense?

Well, that sort of depends. As a purely defensive handgun...not as much as you'd think. Placement and a reliably expanding bullet matter more than caliber, and you have to remember that when 10mm was designed, there weren't that many quality hollowpoints for autoloaders. A big, fast bullet is how you made up for that, and modern .40 and 9x19mm ammunition is light years ahead of where it was in the 1980s and are much cheaper.

Not only that, but the truth about handguns in general is that they aren't one-shot-stoppers even in the more powerful calibers. Studies have found even .44 Magnum fares about as well as .45 ACP or 9mm in defensive shootings. Serious permanent wound cavities don't form until bullets hit at least 2,000 FPS and handgun rounds don't really get up there.

So 10mm is not the GRAND ULTIMATE POWERHOUSE that some people insist. It is a very good and incredibly useful handgun round, to be sure. In fact, it does more than almost any other handgun round does.

However, you can carry for protection and then load for handgun hunting, and the stouter loadings of 10mm are certainly capable for this task. The 10mm comes close, in this regard, to a do-it-all handgun, though jacks of all trades are often eclipsed by specialized tools in specialized roles.

Then again, if you enjoy shooting 10mm, then none of this matters! Seriously. Another truth about handguns is that people like what they like, and if you happen to enjoy shooting and are accurate with a 10mm, then that's what you should have. If you've filled the freezer year over year with one, carry on doing so.

But let's not go believing anything fantastical.

Sam Hoober  

About The Author

Born in southeastern Washington State, Sam Hoober graduated in 2011 from Eastern Washington University. He resides in the great Inland Northwest, with his wife and child. His varied interests and hobbies include camping, fishing, hunting, and spending time at the gun range as often as possible.

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