Brownells BRN-4 Bolt Carrier Group Phosphate & Chrome

BRN-4A(R) Compelte Bolt Carrier Group with Manganese Phosphate Carrier and Chrome Bolt Now offered with a chrome bolt and manganese phosphate carrier, this version of the BRN-4A(R) Bolt Carrier Group is a great upgrade for any BRN-4 or replacement part for an MR556 or 416 rifle. The chrome bolt and cam pin make for easy cleaning and offers a great looking surface finish. The extractor has a phosphate finish, as this allows for a "grippier" interface with the brass, ensuring reliable and consistent extraction. The phosphate carrier is hardened to hold up to extreme firing schedules, such as sustained full auto fire. The tail of the carrier is enlarged to prevent any tiltin Mfg: Brownells