The MUR is a flattop upper receiver with thicker walls than a standard upper to provide a more rigid platform for greater stability, better accuracy, longer service life, and improved reliability. Precision machined from a fully heat-treated and cryogenically stress-relieved aluminum forging, before hand finishing to final dimensions. All critical interface points are 100% compatible with mil-spec select-fire AR-15/M16/M4 components and lower receivers, and will fit most commercial semi-auto lowers. A slick, dry-lube coating over the hard-anodized finish further guards against surface wear and helps ensure smooth operation of bolt/carrier and other internal components. Comes with true MIL-STD 1913 Picatinny rail with 13 cross-slots, plus forward assist and ejection port door pre-installed. Gunsmith installation recommended. Includes M4-type feed cuts. Available with or without forward assist.

SPECS: 7075 T6 aluminum, Type III, Class 2 hardcoat anodized, dry lube coating, matte black. .250" dia. pivot/takedown pin holes.