Brownells

BRN-4® 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-4® 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 tilting from the piston impact. The full length carrier is an M16 type, and also has the MR556 cutout, making it compatible with MR556 and 416 upper receivers.

SPECIFICATIONS/ INCLUDES:

• 8620 steel carrier - Manganese phosphate finish
• 9310 steel bolt - Chrome finish
• 4340 steel Extractor - Manganese phosphate finish
• S7 tool steel Ejector - Manganese phosphate finish
• 8740 steel Firing pin - Chrome finish
• Extractor spring with black insert
• Extractor o-ring, black type
• Firing pin spring
• Firing pin retaining pin