Factory S&W M&P 15 platform dedicated to 300 Blackout. Chrome-lined barrel optimized for both supersonic and subsonic 300 BLK loads. Type: Carbine Action: Semi-Automatic Caliber: 300 Blackout Capacity: 15 Year introduced: 2013, USA Weight: 112 oz Overall length: 32" Status: Active Intended use: Hunting, Home Defense, Sport Shooting