The HK MR556A1 is the semi-auto civilian version of the HK416, one of the most respected military assault rifles. Features the same cold-hammer-forged barrel and piston operating system as the military version. Type: Semi-Auto Rifle Action: Gas-Operated Caliber: 5.56x45mm Capacity: 30 Year introduced: 2010, Germany Weight: 8 oz Overall length: 36.5" Status: Active Military use: Yes Intended use: Tactical, Precision, Collector