The MORIARTI AR-74 7.62x39 5 in Micro Pistol Upper Assembly delivers compact power and versatility for any AR pistol build chambered in 7.62x39. Precision-machined and suppressor-ready, this upper features a 5-inch 4150 Chrome Moly Vanadium barrel with a black nitride finish and a 1:10 twist, making it ideal for stabilizing both standard and heavier projectiles. This upper is built on a billet A3 flat top receiver with forward assist and dust cover, offering enhanced durability and function. The slim 4-inch MLOK handguard provides a lightweight, free-floating rail system for mounting accessories. A standard A2 flash hider is pre-installed to help reduce muzzle flash. Note: This upper does not include a bolt carrier group (BCG) or charging handle, giving you the flexibility to complete your build to spec. Specifications for Moriarti AR-15, 7.62x39mm, 5 inch Upper Receiver: Manufacturer: Moriarti Caliber: 7.62x39mm Barrel Length: 5 in Barrel Profile: Government Gas System Length: Micro Barrel Twist Rate: 1-10 Firearms Threads Per Inch: 5/8x24 Muzzle Device: A2 Flash Hider Finish: Nitride Gun Model: AR-15 Fabric/Material: 4150 Chrome Moly Vanadium Gas Block Journal Size-Diameter: .750 in Handguard Length: 4 in Gun Rail: M-LOK Gun Make: AR Platform Package Contents: Moriarti AR-15, 7.62x39mm, 5 inch Upper Receiver What firearm models does the manufacturer say Moriarti AR-15, 7.62x39mm, 5 inch Upper Receiver is compatible with? The manufacturer says that Moriarti AR-15, 7.62x39mm, 5 inch Upper Receiver is compatible with AR-15