The AR-15 is America’s longest serving service rifle and has a deserved reputation for performance and reliability. However, as with any machine, parts can fail. While not a particular weak point (10,000 round counts are a reasonable minimum) AR-15 bolts can break. One potential point of failure is the center hole fitting the cam pin.
HM Defense designs, develops, and produces AR rifles and parts that feature a number of their own patent-pending technologies. The company manufactures and final machines rifle components in-house in their Mt. Orab, Ohio facility. To improve bolt longevity, HM Defense designed their HMB Bolt, an enhanced durability part for M16/AR-15 and AR-10 rifles. The HMB Bolt corrects a natural weak point in existing bolts where the cam pin hole passes through. Under extensive use, standard bolts can fail there. The HMB Bolt eliminates the pass-through cam pin hole and replaces it with a socket and tapered pin. This reinforces a natural weak point by significantly increasing the amount of metal and strength at the cam pin location.
Read the rest of this entry »