The Geissele Super Duty 14.5" Heavy Barrel (.750 Journal) Black Stripped Upper Receiver is a premium AR-15 upper foundation built around a cold hammer forged, chrome-lined 14.5-inch heavy barrel with a .750? gas journal and 1:7 twist for excellent stability and performance with a wide range of 5.56×45 mm NATO ammunition. Featuring a mid-length gas system with a Super Compact gas block for smooth cycling, this stripped upper arrives ready for your choice of handguard, charging handle, bolt carrier group (BCG), and muzzle device. Finished in durable black anodize and equipped with a Picatinny rail on the receiver, the 08-661B provides a rugged, optics-ready base for custom rifle builds when paired with a compatible lower. Built in the USA, it’s ideal for precision-oriented and duty-grade configurations. Geissele Super Duty 5.56mm 14.5" Heavy Bbl (.750 Journal) Black Stripped Upper Receiver (No Charging Handle, Muzzle Device, or BCG) 08-661B