Andro Corp Industries ACI-15 M4 Semi Automatic Rifle 5.56x45mm NATO 16" Black Threaded Barrel Flat Dark Earth Frame Black Pistol Grip - The Andro Corp Industries ACI-15 M4 is a modern sporting rifle built with the high quality components and are made to perform multiple uses under a wide variety of conditions. High quality components like a 7075 Forged lower, 4150 CMV melonite Barrel, QPQ Corrosion resistant finish, and 7075 T6 MilSpec Dry Film Lubed Upper make these rifles durable and dependable for the long haul.