Initially developed for U.S. Special Operations Command, the HK Mark 23 for sale was the first .45 ACP pistol to enter American military service since the 1911A1. The HK Mk 23 meets the stringent requirements of a combat handgun, enduring 30,000 rounds of +P ammunition run through its barrel in testing, providing operators match grade accuracy, and unrelenting reliability equal to the finest custom-made pistols in the civilian market.