HM Defense AR-15 5.56/.223 HMB Battle Bolt Carrier Group – Black Nitride

The HMB Bolt corrects a natural weak point in existing Mil-Spec M16, AR-10 & AR-15 bolts where the cam pin hole passes through the bolt. Under extensive use, including the stress of combat, a standard Mil-Spec bolt can fail at the cam pin hole location. The HMB Bolt by HM Defense eliminates the pass-through cam pin hole and replaces it with a cam pin socket and tapered cam pin design. This new patent-pending 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! Additionally, the HMB Bolt 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.

BOLT CARRIER GROUP SPECIFICATIONS

• Manufacturer: HM Defense
• Manufacturer Part #: HMB-BCG-AR15
• Type: Bolt Carrier Group
• Color: Black
• Finish: Nitride
• 5.56 NATO – 223 Rem – 300 AAC
• 9310 Steel
• 4340 Hardened Steel Cam Pin
• Nitride Black Finish