Each ArmaLite Complete Upper Assembly includes a forged upper receiver assembly, barrel assembly, bolt carrier group and charging handle assembly. All complete upper assemblies are test fired as complete rifles before shipping.
AR-10 uppers use 7175-T74 aluminum.
.750 at the journal (under the gas block)
Caliber: .308/7.62 X 51mm NATO
Barrel: 16" Double Lapped, Chrome Lined, 4140 steel, M-4 Feed Ramps
Rifling Twist: RH 1:11.25"
Muzzle Device: Flash Suppressor, Threading: 5/8"-24
Front Sight Base: A2 Front Sight
Upper Receiver: Forged Flattop with Picatinny Rail 7175-T74 Aluminum
Finish: Hard Anodized Aluminum, Manganese Phosphated Steel