CORE 15® M16 BOLT CARRIER GROUP - PARKERIZED •.223/5.56 NATO •M16 profile •Shot peened •Nickel boron coated •Magnetic Particle Inspected (MPI) bolt •Mil-Spec Carpenter 158® steel bolt •M16 chrome lined 8620 steel carrier •Chrome lined gas key •Gas key hardened to USGI specs •Gas Key Grade 8 hardened fasteners •Mil-Spec staked gas key •Tool steel extractor upgrade •Extractor spring •Includes bolt cam pin firing pin & retaining pin
