Sig M400 Tread variant chambered in 300 Blackout with 16-inch barrel. A factory-complete dedicated 300 BLK build. Type: Carbine Action: Semi-Automatic Caliber: 300 Blackout Capacity: 30 Year introduced: 2020, USA Weight: 112 oz Overall length: 32" Status: Active Intended use: Hunting, Home Defense, Sport Shooting