This handgun was developed under request from US SOCOM (Special Operations Command). The extreme ruggedness, reliability, and match-grade accuracy of the HK MK23 makes this hand gun the a viable choice for all US special forces. The gun is quite heavy, and some US special operation units prefer to use HK's USP Tactical instead of the MK23, mostly due to its smaller size and weight.

The MK23 is chambered for the venerable .45ACP cartridge, which provides greater stopping power than NATO-standard 9mm cartridges. The MK23 is designed to safely and reliable fire most powerful .45ACP +P ammunition, either with ball (FMJ) or expansive (JHP) bullets. The MK23 is a short recoil operated, locked breech semiautomatic pistol. The barrel locks to the slide using one single lug, which fits to the ejection port in the slide. The patented dual recoil springs arrangement allows for decreased felt recoil and increased service life of pistol. Frame of the gun is made from high-strength polymer. The double action trigger system features a separate decocker lever, an ambidextrous safety, which allows for "cocked and locked" carry, and a slide stop.

The MK23 is usually issued with quick-detachable silencers, made in USA by Knight's Armament Company, and with laser pointing module which installs on the underbarrel rails. The specially designed sound and flash suppressor on this HK MK23 virtually eliminates muzzle flash. An essential part of any DUTA mission requiring both firepower and discretion.