The M-15A4 LEC Carbine Complete Upper Assembly with A2 front sight features a chrome lined barrel with M203 step down. The Picatinny Rail on the upper receiver allows rapid and repeatable interchange of removable iron or scope sights.
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.
M-15 Uppers use 7075-T6 Aluminum.
.750 at the journal (under the gas block)
Model: Commercial ISP Carbine Upper Assembly
Caliber: .223/5.56 X 45 mm NATO
Barrel: 16″ Chrome Lined\Chrome Moly Vanadium MIL-B-11595-E with M203 Step Down
Rifling Twist: RH: 1:9″
Muzzle Device: Flash Suppressor, Threading:1/2″ – 28
Front Sight Base: A2 Front Sight Assembly
Upper Receiver: Forged Flattop with Picatinny Rail, 7075-T6 Aluminum
Finish: Hard Anodized Aluminum, Manganese Phosphated Steel