Pistol-configuration M&P15 in .300 Blackout with a 9-inch barrel and SB Tactical pistol brace. Combines S&W's M&P15 pistol platform with the suppressor-optimized .300 BLK cartridge for a compact CQB and suppressor-host package. Type: Semi-Auto Pistol Action: Gas-Operated Caliber: .300 Blackout Capacity: 30 Year introduced: 2014, USA Weight: 5.8 oz Overall length: 24.5" Status: Active Intended use: Home Defense, Suppressor Host, Range