ARD
COMPLETE
AR-15
ARD BOLT CARRIER GROUP 

CARPENTER STEEL C158 BCG
556 / 223

CROME LINED
BOLT CARPENTER STEEL MPI TESTED

Complete bolt carrier group for 556 rifles. Includes gas key

cam pin, firing pin, firing pin retaining pin, and 556 bolt head assembly.

An AR-15 Bolt Carrier Group (BCG) is the powerhouse of the rifle, cycling rounds, extracting spent casings, and resetting the hammer. A C158 (Carpenter 158) bolt is the U.S. Military (mil-spec) standard steel. It undergoes shot-peening, High Pressure Testing (HPT), and Magnetic Particle Inspection (MPI) to prevent stress fractures