M&P 15 Sport II chambered in 300 Blackout with a 16-inch 1:8 twist barrel. The 300 Blackout cartridge uses the standard AR-15 bolt and magazines — only the barrel differs. Suppressor-compatible performance at an entry-level price. Type: Rifle Action: Semi-Automatic Caliber: 300 Blackout Capacity: 30 Year introduced: 2020, USA Weight: 25.6 oz Overall length: 35" Status: Active Intended use: Home Defense, Recreational Shooting