10mm Auto
Also called: 10mm, ten-mil, 10mm Automatic
A powerful semi-automatic handgun cartridge, popular with hunters and hikers in bear country who want more punch than a 9mm.
- Type
- Handgun
- Bullet diameter
- .400 in
- Case length
- 0.992 in
- Overall length
- 1.26 in
- Typical bullet weights
- 155 to 220 grains
- Typical muzzle velocity
- About 1,150 to 1,450 fps
- Recoil
- Moderate recoil
- Quarry
- Backup & defense, Deer, hogs & pronghorn
- Typical range
- Defensive use at close range; some hunters take deer at short distance where handgun hunting is legal
- Availability
- Common and growing
Safety: Do not confuse the 10mm Auto with the shorter .40 S&W. The two use the same bullet width, but they are not interchangeable.
What it is good for
- Backup protection against animals and people while hunting or hiking.
- Handgun hunting at close range where legal.
- Shooters who want more power than a 9mm in a semi-automatic.
Where it falls short
- Recoil is stronger than a 9mm or .45 ACP, which affects follow-up shots.
- Ammunition costs more, and weaker .40 S&W-level loads are sometimes sold as '10mm' by mistake.
- Handguns are limited in range, so shooting skill matters.
Easily confused with
- .357 Magnum: a revolver cartridge of similar power with a narrower bullet.
- .45 ACP: another popular semi-automatic cartridge with a wider, slower bullet.
Field notes
The 10mm Auto came from the 1980s and has found a second life among hunters and outdoor carriers. It is a flat-shooting, high-power semi-automatic cartridge.
Related guides
Numbers are typical factory-load figures, not guarantees. Use only ammunition that matches the cartridge stamped on your firearm and is made by a reputable manufacturer, and follow the manual. Legal game cartridges, minimum calibers, and non-toxic shot rules differ by state and area. Check your state's current regulations; our state resources directory links to each state's official rules. Not sure which rifle to buy? Try our hunting rifle wizard.