Wilson Combat's BILLet-AR matched receiver set was engineered from the ground up to address structural design weaknesses in standard USGI receivers and enhance overall tolerances which improve shot to shot consistency. The BILLet-AR upper receiver has a precise bolt raceway for smoother chambering and more rigid receiver walls to reduce firing flex. The BILLet-AR lower receiver has been enhanced with an oversize magazine well for smooth reloads and an integral trigger guard for gloved use and added lower receiver strength. The set is CNC machined from billet 7075-T6 aerospace aluminum with a Picatinny top rail, shell deflector, and a smooth side profile without a forward assist. It has M4-style extended feed ramps for excellent reliability with a wide variety of calibers, precision-threaded receiver and reamed pin holes, and hex screw bolt catch retention. This AR-style model has a black Armor-Tuff finish.