Rock River Arms LAR-15 National Match A4 with 20-inch Wylde chamber barrel, two-stage trigger, and free-float tube. Purpose-built for service rifle competition. Type: Rifle Action: Semi-automatic Caliber: 5.56x45mm Capacity: 20 Year introduced: 2005, USA Weight: 80 oz Overall length: 39.5" Status: Active Intended use: Service Rifle Competition