CMMG Mk4 RCE in .300 Blackout, applying the company's standard AR-15 quality to the suppressor-optimized cartridge. Mid-length gas system on the 16-inch barrel provides reliable cycling with both supersonic and subsonic loads. Type: Rifle Action: Semi-Automatic Caliber: .300 BLK Capacity: 30 Year introduced: 2015, USA Weight: 96 oz Overall length: 32.5" Status: Active Intended use: Home Defense, Suppressor Host, Hunting