Stag 15 Tactical 10.5" uppers are chambered in 5.56 NATO and built around a 10.5" 1/7 twist barrel, Stag 9" M-LOK SL Handguard and 7075 T6 Aluminum receivers. These uppers use a carbine-length gas system that is combined with a low-profile gas block, which provides reliability under any condition.The free-floating Stag 9" M-LOK SL Gen 2 Handguard features a slim, lightweight profile that offers increased ergonomics, maximum airflow, and modularity while continuing to provide the utmost strength and durability. The handguard provides uninterrupted picatinny rail along the top, which allows room for sights, optics and accessories the shooter may require.This upper half does not include a BCG or Charging Handle.Action: Semi-Auto Direct ImpingementCaliber: 5.56 NATOTwist Rate: 1/7 Button RifledMuzzle Device: A2 Flash HiderBarrel: 10.5", 4150 CMV, Black NitrideHandguard: Stag 9" M-LOK SLReceiver Material: Forged and Mil-Spec 7075 T6 Aluminum with Type 3 Hard Coat AnodizeBolt Carrier: NoneGas System: Carbine-Length with Low Profile Gas BlockCharging Handle: None