The M&P15 Whisper is a factory .300 Blackout AR-15, purpose-built for suppressed operation. Features a 16-inch barrel optimized for both supersonic and subsonic .300 BLK loads with a carbine-length gas system. The Whisper name references the suppressed-fire application — .300 BLK subsonic loads produce hearing-safe report through a suppressor, making this configuration popular for home defense and hunting. Type: Rifle Action: Semi-Automatic Caliber: .300 Blackout Capacity: 30 Year introduced: 2013, USA Weight: 6.4 oz Overall length: 35" Status: Discontinued Intended use: Hunting, Tactical, Sport Shooting