Bushmaster XM15-E2 COmplete Lower Receiver Assemblies -Manufactured to latest Military Specifications for the M16 A2 rifle/carbine, -Precision machined high tensile strength 7075 T6 aluminum alloy forging- not a casting, -Exterior is grit blasted to produce a non-reflective matte finish, -Protective finish: Hard Anodize Military A8625, Type III, Class II finish- lusterless (flat, approximate black no. 37038 table IX- with a nickel acetate final seal coat), -Latest M16 A2 design reinforcement area around front pivot pin and reinforcing ridge over buttstock attachment area, -Full "fence" around mag release button protects from accidental release, -Bushmaster Mil. Spec. Lower Receivers are guaranteed for fit and function- and this guarantees the interchangeability designed into the weapons system if you ever buy a 2nd upper/barrel assembly, -Standard military push pin design with captivated pins front and rear.
