HM Defense has released the HMB Bolt, an enhanced durability bolt for M16, AR-10 and AR-15 rifles. The HMB Bolt corrects a natural weak point in existing Mil-Spec M16, AR-10 and AR-15 bolts where the cam pin hole passes through the bolt. The HMB Bolt replaces the pass-through cam pin hole with a cam pin socket and tapered cam pin design to remove the weak point of Mil-Spec bolts. It also reduces contact between cam pin and firing pin for smoother operation of firing pin, bolt lugs and aft gas rings. It’s compatible with Mil-Spec M16 and AR-15 BCGs and can be installed as a drop-in bolt replacement in any existing M16 or AR-15 rifle.