AR-556 Pistol chambered in .300 Blackout with an 8.5-inch barrel. The .300 BLK cartridge reaches near-peak velocity in short barrels, making this a purpose-built suppressor host and CQB platform. Ships with SB Tactical SBX-K pistol brace. Type: Semi-Auto Pistol Action: Gas-Operated Caliber: .300 Blackout Capacity: 30 Year introduced: 2019, USA Weight: 5.8 oz Overall length: 25.1" Status: Active Intended use: Home Defense, Suppressor Host, Range