The RISE 22 ARC AR-15 Upper Receivers features an exceptionally accurate 18-inch 416R stainless steel threaded barrel. Platform: AR-15 Caliber: 22 ARC Gas System: Rifle-length Barrel Twist: 1:7 Barrel Thread Pitch: A 1/2"x28 Barrel Length: 18" Handguard Length: 15.25" Colors & Finish: Black (Type III Hardcoat Anodize) Key Features Barrel: 18-inch 416R stainless steel, button-rifled, air-gauged and tested; threaded Handguard: Free-floating skeletonized aluminum with continuous 12 o'clock Picatinny rail, MLOK slots, four threaded steel sling swivel QD inserts, a snag-free front, and patent-pending attachment lock to maintain your zero Charging Handle: RISE ambidextrous charging handle for right- or left-handed operation and improved ease of use with optics and gloves Bolt Carrier Group: Premium BCG with 9310 bolt, individually MPI tested, staked gas key, durable black nitride finish Receiver: Forged billet aluminum