The AR-556 Pistol features a 10.5-inch barrel with a SB Tactical SBX-K pistol brace, making it NFA-exempt while delivering carbine-length ballistics in a compact package. Uses the same forged aluminum receivers as the full-size AR-556. Type: Semi-Auto Pistol Action: Gas-Operated Caliber: 5.56x45mm Capacity: 30 Year introduced: 2018, USA Weight: 5.9 oz Overall length: 26.5" Status: Active Intended use: Home Defense, Range