The Mk 12 Special Purpose Rifle Mod 0 is a SOCOM-developed designated marksman rifle built on the M16 lower receiver. Features an 18-inch SPR barrel with a 1:8 twist, free-float handguard, and Leupold Mk4 optic. Used by Navy SEALs and Army Special Forces. Type: Semi-Auto Rifle Action: Gas-Operated Caliber: 5.56x45mm Capacity: 20 Year introduced: 2002, USA Weight: 7.9 oz Overall length: 35" Status: Active Military use: Yes Intended use: Military, Special Operations, Precision