Geissele Automatics Reliability Enhanced BCG Features The Geissele Automatics Reliability Enhanced BCG is manufactured as a full mass full auto rated carrier group for 5.56mm M16/M4 pattern rifles giving it broader compatibility and reliability margin than a lightweight carrier. The gas key is properly torqued and staked then chrome lined and nano coated to resist carbon buildup and wear over thousands of cycles. Extended upper rails on the carrier body add stability inside the receiver which Geissele states dramatically improves feeding reliability. The cam pin is machined from H13 tool steel the same material used in some medical instrumentation then coated with Nanoweapon for maximum corrosion and wear resistance. Included with every carrier is the Geissele Stressproof Bolt forged from a special Carpenter 158+ alloy developed directly with Carpenter Steel metallurgists for a cleaner more consistent material. Forging the bolt manipulates the grain structure of the steel resulting in a bolt rated for up to five times the service life of a standard mil spec bolt. Each bolt is rigorously inspected high pressure tested and mag particle inspected before being coated in Nanoweapon for long term durability. Shooters building a duty competition or high round count training rifle will appreciate the added reliability margin this Black finished carrier group provides. Geissele Automatics Reliability Enhanced BCG Specifications Manufacturer: Geissele Automatics Model: Reliability Enhanced BCG Type: Bolt Carrier Group Compatible Hosts: AR-15 Caliber: 5.56x45 NATO Color: Black Finish: Matte Weight: 0.5 lbs Available At: GrabAGun