The HK Mark 23, officially the Mk 23 Mod 0, was developed for the US Special Operations Command SOCOM pistol program. It is one of the largest and most over-engineered combat pistols ever produced, featuring a corrosion-resistant finish, O-ring barrel for superior suppressor performance, match-grade accuracy, and extreme reliability standards. Issued to US Navy SEALs and SOCOM units. Type: Semi-Auto Pistol Action: DA/SA Caliber: .45 ACP Capacity: 12 Year introduced: 1996, Germany Weight: 42 oz Overall length: 9.65" Status: Active Military use: Yes Intended use: Special Operations, Suppressor Host, Military Use, military, duty