While a lot of people in the U.S. like the old .45acp, many speak very highly of the 10mm AUTO.

This cartridge was developed in the early 1980s. It was heralded as the perfect service round for law enforcement and military use by well-known .45 guru Jeff Cooper. Many here feels it's currently the most versatile and powerful cartridge you can fit into a pistol of reasonable size and weight. Loaded ammo is available not only in many bullet weights & styles, but also in power levels.

The 10mm offers more knock-down punch than a 45acp or 9mm, while also, in certain pistols, having a mag capacity level closer (or equal) to a 9mm - except in the U.S. where, in the absence of owning any so-called high capacity "pre-ban" mags, a buyer is typically limited to "post-ban" 10rd mags (regardless of caliber).

10mm pistols are available from Glock (20 & 29), Kimber, Dan Wesson, and Tanfaglio (the Witness, in large & compact models). Some older used guns also exist in 10mm, like the S&W series (10XX - 1006; 1076), and Colt's Delta Elite)