5.56 Black Nitride BCG HMB

Semi-Auto/ Full Auto M16 bolt carrier group made using MILSPEC 8620 quality steel on in-house CNC machines. All carriers are then heat-treated, and Black Nitride coated

- Standard MIL-SPEC carrier with additional care taken during machining process

- Sharp edges and rough finishes eliminated. Will NOT shred fingers and operates smoothly

- Standard Gas Key (torqued to spec, not staked)

- The HMB Bolt by HM Defense eliminates the pass through cam pin hole and replaces it with a cam pin socket and radiused cam pin design. The new patented design eliminates the natural weak point of Mil-Spec bolts by significantly increasing the amount of metal (and strength) at the cam pin location. The result- NO MORE BROKEN BOLTS! The HMB Bolt also reduces contact between cam pin and firing pin, enabling smoother operation of firing pin, bolt lugs and aft gas rings. The new cam pin socket also retains lubrication for extended operations.

Young Manufacturing does not stake carrier keys, read about why here.