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.
8" Gas System
M-15 Uppers use 7075-T6 Aluminum.
.750 at the journal (under the gas block)
Caliber: 6.8mm Remington SPC II
Barrel: 16" Double Lapped Chrome Lined\Chrome Moly Vanadium MIL-B-11595-E with M203 Step Down, Threaded 5/8x24, M-4 Feed Ramps
Rifling Twist: 1:11"
Muzzle Device: Flash Suppressor
Front Sight Base: Gas Block with Picatinny Rail
Upper Receiver: Forged Flattop with Picatinny Rail & Laser Engraved Rail Numbering, 7075-T6 Aluminum