10mm Auto: Good Self-Defense Round?


In a recent article, I covered the pros and cons of many rounds that are commonly used for self-defense.

Due to the large degree of choices, I had to leave out a few. The most commonly asked about choice I left out was the 10mm Auto.

It is (depending on who is selling it) the seventh to ninth most popular self-defense caliber, by volume of JHP bullets sold.

I will address that today, beginning with a bit of history of the cartridge.

Brief History of 10mm Auto

Jeff Cooper (yes that Jeff Cooper) invented the chambering for the up-and-coming Bren Ten pistol.

As most of you know (or know by not knowing), the Bren was anything but a huge success. That did not end the life of the 10mm.

In reaction to the 1986 Miami Bank shootout, the FBI demanded stronger hitting power from their pistols.

In the 1986 shootout, two FBI agents were killed and five more wounded by two bank robbers armed with semi-auto rifles and wearing double layers of soft armor.

The FBI adopted the 10mm round and associated pistols to up the firepower of their agents.

In time, they un-adopted the round, as many of the agents with small hands and minimal training were not able to handle the strong recoil or pass qualifications.

Also, the chosen platform, the S&W 1076, was not reliable.

These factors lead to the neutering of the 10mm with the creation of a softer shooting variant, the .40 S&W.

This was then adopted by many LEO agencies in the U.S. and abroad.

10mm S&W pistol, gloves, glasses and ammo
Load Bullet Weight Velocity Energy
Original FBI Load 170-Grain 1,300 fps 638 ft/lbs
FBI .40 S&W Load 180-Grain 950 fps 360 ft/lbs

10mm Auto for Self-Defense

For many years, I drank the .40 S&W Kool-Aid. And to be fair, it is not an awful round.

It just doesn’t live up to anything resembling its potential and although I still own the GLOCK 22 I carried, it no longer has a place as a carry option.

If I am going to carry something that runs a 0.400 bullet, it would be a 10mm.

That brings us to the value of 10mm as a carry round.  

From third-party ballistic testing, as with almost all other calibers, the choice of round makes a huge difference.

In this test, the gun used was a GLOCK 20 (4.6” barrel).

They chose this for several reasons, but it seems as if most people who carry a 10mm have at least a 4.5” barrel.

There are only two commonly available options in the subcompact category, the GLOCK 29 (3.8”) and the EAA Witness Compact (3.6”).

Both of these severely hamper performance, much like the .357 Magnum with a two-inch barrel.  

Essentially, 10mm in a short barrel creates .40 S&W performance with an increase in muzzle blast, muzzle flip and recoil, with no performance bonus.

10mm Auto GLOCK 20

Load Testing

Best Options

The best choices tested (in alphabetical order):

Load Penetration Expansion Velocity
Barnes 155-Grain VOR-TX 12.5 Inches 0.81 Inches 1,080 fps
Hornady 155-Grain XTP 14 Inches 0.68 Inches 1,344 fps
Hornady 180-Grain XTP 16.9 Inches 0.64 Inches 1,158 fps
SIG Sauer 180-Grain V-Crown 19.4 Inches 0.76 Inches 1,138 fps
Speer 200-Grain Gold Dot 19.7 Inches 0.68 Inches 1,029 fps
Winchester 175-Grain Silvertip 16.2 Inches 0.68 Inches 1,143 fps

Of these, I would likely run the Barnes 115-grain VOR-TX, unless I had serious concerns regarding barrier penetration.

My choice would be influenced by the lack of overpenetration potential, massive expansion and relatively tame recoil impulse.

This should result in quickly stopping the bad guy, while facilitating follow-up shots, should they be needed.

For those wanting additional barrier penetration, the SIG Sauer or Winchester Silvertip might be the better choice.

I would be willing to carry any of the above, with the possible exception of the Hornady 155-grain XTP.

I would need to determine how much recoil penalty the 1,344 fps velocity creates.

I don’t see the extra velocity as useful, since it does not improve performance.

SIG Sauer Elite Performance Ammo Box

Worst Options

The worst choices for self-defense (in alphabetical order):

Load Penetration Expansion Velocity
Buffalo Bore 200-Grain 32+ Inches 0.04 Inches 1,110 fps
Federal 180-Grain Trophy Bonded 32+ Inches 0.4 Inches 1,227 fps
G2 Research 115-Grain RIP 12.2 Inches 0.4 Inches 1,240 fps

In fairness to the Buffalo Bore and Federal Trophy bonded, they are not designed as self-defense rounds.

They are supposed to be used a hunting rounds for CPX3 or larger game.

The complete lack of expansion still concerns me, but the penetration potential is more important against a feral hog.

These types of bullets also tend to expand on contact with bone, which was not tested here.

I see no reason for the G2 round. It barely has adequate penetration and zero expansion.

Many people chase velocity with low-weight for caliber projectiles, but this doesn’t even offer that.

Buffalo Bore Ammo Box

Other Options

There are other choices in the middle of the pack and certainly a lot of choices that were not tested.

Not to mention, handloaders are able to create significantly more powerful loads.

I would mention that might not be the best choice for self-defense (against two-legged varmints).

The 180-grain 1,350 fps loads will do huge damage (assuming good expansion), but the follow-up time will be much longer.

These certainly have a place against dangerous game. The other thing is, an unfriendly DA can use that against you in court.

Even if you don’t face the full effect, why put yourself through the process on an otherwise good shoot?

Do you like to use 10mm auto for self-defense? Let us know in the comments below!

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