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)