Economy version of the SR-556 with a single-stage piston and reduced feature set to hit a lower price point. Lacks the chrome lining of the original SR-556 but retains the piston operating system and cold hammer-forged barrel. Type: Semi-Auto Rifle Action: Piston-Operated Caliber: 5.56x45mm Capacity: 30 Year introduced: 2011, USA Weight: 7.6 oz Overall length: 35.5" Status: Discontinued Intended use: Range, Patrol