Andro Corp Industries U556103ML 5.56 NATO 10.3" M-LOK Complete Upper

The Andro Corp Industries U556103ML is a complete 5.56x45mm NATO AR-15 upper receiver assembly built around a compact 10.3" barrel, making it a turnkey platform for short-barrel rifle and AR-pistol builds. The barrel is machined from 4150 Chrome Moly Vanadium steel with a Melonite treatment and finished in corrosion-resistant QPQ black.

The bore features a 1:7 twist rate to stabilize a wide range of bullet weights, M4 feed ramps for reliable feeding, and is threaded 1/2x28 to accept the included A2 flash hider or any compatible muzzle device. Up front, the upper is paired with a slim free-float M-LOK handguard that delivers plenty of real estate for accessories, lights, lasers, and grips without adding bulk.

Internally, the upper uses a carbine-length gas system fed through a low-profile .750" gas block for smooth cycling with the included M16 bolt carrier group. Overall length measures 18.75", keeping the package compact and maneuverable. The U556103ML drops onto any mil-spec AR-15 lower receiver to deliver a compact 5.56 NATO upper ready for pistol, SBR, or compact rifle builds.