Fully assembled and ready to drop into any mil-spec AR-15, M-16 or M-4 upper receiver, this full auto profile bolt carrier group from Fail Zero is a great choice for any upgrade or new build. EXO nickel boron coats all critical parts and provides permanent dry lubricity and corrosion resistance. This coating reduces friction and wear. It is the perfect way to improve the overall performance of any rifle.

NOTE: use of this bolt carrier group in a semi auto rifle does not convert it to full auto fire.

Specifications and Features:
5.56 NATO/.223 Remington compatible bolt and extractor
Full auto profile bolt carrier
Single stage semi-auto hammer
Cam pin
Carrier key
Firing pin