Geissele Automatics Reliability Enhancement Kit Features The Geissele Automatics Reliability Enhancement Kit is built around the Reliability Enhanced Bolt Carrier Group a full-mass full-auto rated M16/M4 pattern carrier machined from mil-spec 8620 steel. Extended upper rails on the carrier add stability and dramatically increase feeding reliability compared to a standard carrier profile. The cam pin is machined from H13 medical steel and coated with Nanoweapon Geissele s proprietary Chrome-Nitride finish for maximum corrosion and wear resistance. The Geissele Stressproof Bolt is forged from Carpenter 158+ steel developed in partnership with Carpenter Steel metallurgists and is rated for roughly five times the service life of a mil-spec bolt. Every bolt undergoes high pressure testing and magnetic particle inspection before leaving the factory and the entire REBCG is finished in Nanoweapon for reduced carbon fouling and easier cleaning. The kit also includes the Super 42 Braided Wire Buffer Spring paired with an H3 buffer weight tuned to complement the reliability enhancements built into the carrier group and bolt. This combination smooths the operating cycle and reduces the wear that accelerates failures in a hard-use carbine. Manufactured at Geissele s state-of-the-art facility in North Wales Pennsylvania the Reliability Enhancement Kit gives AR-15 owners a proven tested upgrade path for their rifle s operating system. Geissele Automatics Reliability Enhancement Kit Specifications Manufacturer: Geissele Automatics Model: Reliability Enhancement Kit Type: Bolt Carrier Group Caliber: 5.56x45 NATO Compatible Hosts: AR-15 Carrier Type: M16 Color: Black Finish: Matte Buffer Weight: H3 Weight: 1.2 lbs Available At: GrabAGun