10mm Auto Explained: Full-Power, Subsonic and the Pistols That Shoot It

10mm Auto has a loyal following. Hikers carry it in bear country, hunters use it where it is legal, and plenty of people just like shooting it at the range. This guide covers what the cartridge is, how the different loads compare, and what to look for in a pistol. You can see live 10mm ammo listings any time.

The chart at the top shows which bullet weights fill the most in-stock 10mm listings on Gun Search Engine right now.

What 10mm Auto is

10mm Auto is a semi-auto pistol cartridge built for more power than the common service rounds of its day. Ammo boxes may call it 10mm, 10mm Auto or 10mm Automatic. They are all the same round.

The FBI adopted 10mm for a time, then asked for a softer load that was easier to control. That lighter load led to .40 S&W, which uses the same bullet width in a shorter case. The two are not interchangeable. Only fire the cartridge stamped on your barrel.

“Same bullet width as .40 S&W. A longer case and a lot more room to push.”

Full-power, lighter and subsonic loads

10mm ammo covers a wide range. The same caliber on the box can mean very different recoil and very different uses.

• Full-power loads: the hot end of the range. Makers like Underwood are known for them. People pick these for woods carry and for hunting where a handgun is legal. Expect sharp recoil.
• Lighter loads: often sold as range or practice ammo. They feel closer to .40 S&W and are easier on you and your gun over a long day.
• Defense loads: hollow points built to expand. Hornady and other big makers sell them in both full and milder versions.
• Subsonic loads: usually heavier bullets loaded to stay below the speed of sound. They are quieter through a suppressor, where suppressors are legal.

“Pick the load first. A full-power box and a subsonic box do very different jobs.”

What to look for in a 10mm pistol

Several big makers chamber pistols in 10mm, from polymer striker guns to steel-frame designs and a few revolvers. Browse 10mm handguns to see what is in stock today.

• Size and weight: a full-size or heavier pistol soaks up more recoil. Compact 10mm guns are handy to carry but harder to shoot fast.
• Grip fit: 10mm magazines are long, so the grip is often thick. Hold one before you commit if you can.
• Barrel length: a longer barrel gets more out of full-power loads. A shorter one is easier to carry.
• What you will feed it: if you will shoot mostly light range loads, almost any 10mm will do. For full-power loads, check that the maker rates the gun for them.
• Holsters and mags: popular models have far more holster and magazine choices. That matters for woods carry.

“A heavier, full-size pistol makes the hot loads much easier to shoot well.”

10mm vs .40 S&W at a glance

• 10mm: more power on tap, more recoil, a bigger gun and fewer choices on the shelf.
• .40 S&W: milder, fits smaller guns and is usually easier to find. Compare live .40 S&W listings.

Ready to compare? See live 10mm ammo listings by brand and bullet weight, or check Underwood and Hornady for two very different takes on the round.