Colt AR-15 Upper Receiver Assembly 5.56x45mm 16″ Barrel Monolithic Rail

Colt AR-15 Upper Receiver Assembly includes a 5.56x45mm 16-inch barrel, free-float monolithic rail, flat-top upper, bolt carrier group, charging handle, A2 flash hider, and flip-up rear sight. This is an upper receiver assembly, not a complete firearm.

Colt AR-15 Upper Receiver Assembly 5.56x45mm 16″ Barrel Monolithic Rail

Colt AR-15 Upper Receiver Assembly is built for buyers who want a factory Colt 5.56x45mm upper with a rigid monolithic rail system. This assembly includes the upper receiver, 16-inch barrel, bolt carrier assembly, charging handle, A2 flash hider, and flip-up rear sight.

The main advantage is the free-float monolithic rail. Because the rail and upper receiver are machined as one continuous platform, optics and mounted accessories sit on a single rail plane instead of separate receiver and handguard sections. That helps buyers who want a cleaner mounting surface and more consistent alignment.

This Colt upper also features a flat-top Picatinny receiver, free-floating barrel, black Parkerized finish, and A2-style muzzle device. It is a strong fit for buyers upgrading an AR-15 lower or replacing a standard upper with a Colt monolithic rail assembly.

This is not a complete rifle. The lower receiver, stock assembly, magazine, and lower parts are not included. Buyers must confirm lower receiver compatibility, caliber marking, headspace and installation requirements, and all federal, state, and local laws before purchase or use.

For compatible ammunition categories, browse Bulk .223 & 5.56 Ammo, compare .223 / 5.56 NATO Ammo, or read the 5.56 Ammo Guide before choosing rifle ammunition. For source product details, use the Colt LE6940 16-inch Monolithic Upper Receiver Assembly reference.

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