Faxon Firearms 5.56 M16 Bolt Carrier Group Features The Faxon Firearms 5.56 M16 Bolt Carrier Group starts with a 9310 tool steel bolt that is fully heat treated for strength and durability under repeated cycling. Every bolt is Magnetic Particle Inspection tested a process that detects surface and near-surface defects before the part ever reaches the rifle giving builders confidence in the part s integrity. A hard chrome coating covers the bolt carrier gas key and cam pin reaching 68 to 72 HRC on wear surfaces for exceptional resistance to friction and corrosion. The carrier body itself is superfinished a process that smooths the metal surface to reduce friction and minimize carbon fouling during extended firing sessions. An S7 extractor is installed complete with spring insert and a crane style O-ring a combination known for improving extraction reliability over the standard configuration. The gas key is secured with Grade 8 fasteners and fully staked a critical step for keeping the key seated and preventing gas leakage during high round counts. This bolt carrier group is full-auto rated making it suitable for both mil-spec AR-15 rifles and M16 platforms that demand a higher standard of durability. Each unit is laser-engraved with the Faxon Shield marking it as a genuine Faxon Firearms component for sale at GrabAGun. Faxon Firearms 5.56 M16 Bolt Carrier Group Specifications Manufacturer: Faxon Firearms Model: 5.56 M16 Bolt Carrier Group Material: 9310 Tool Steel Finish: Nitride / Chrome Extractor: S7 with Spring Insert and O-Ring Compatibility: Full-Auto Rated M16/AR-15 Made In: USA Available At: GrabAGun