Aero Precision AR15 5.56 PRO Series Bolt Carrier Group (BCG)

The Aero Precision PRO 5.56 Bolt Carrier Group BCG is built from the ground up to meet the demands of the most extreme conditions. Each component and manufacturing process of the PRO 5.56 Bolt Carrier Group BCG was deliberately chosen to increase the reliable service life of the Bolt Carrier Group BCG and its components. Bolt The bolt is one of the most important parts of the Bolt Carrier Group BCG. Machined from 9310 steel, a proprietary flash nitride process was chosen to ensure proper heat treatment on the bolt. When properly heat treated, 9310 steel provides superior strength and durability when compared to C158. The cam pin channel is counter bored, eliminating the need for swaging. Swaging is the industry standard, however this process creates more stress on the bolt during manufacturing by displacing material rather than cutting it to the proper dimension from the start. Cam Pin Each PRO cam pin is precision ground after heat treatment to exacting specifications and given a nitride finish. The cam pin features an engraved indexing mark on one side of the cam pin face; a concept that has been popularized by Chad Albrecht at School of the American Rifle. Cam pins traditionally wear more heavily on one side and when installed inconsistently can create excessive wear over time. When the cam pin becomes loose this can create excessive wear on the bolt itself shortening overall life. The indexing mark allows for consistent installation during maintenance which in turn reduces wear on not only the cam pin but the bolt over time to help extend overall service life. Extractor The extractor features a phosphate finish. The extractor is one of the few places where it is beneficial to have a rougher finish as it allows for more positive engagement with the case when pulling it out of the chamber. Carrier Each PRO BCG utilizes a M16 cut carrier and features a nitride finish. Internal critical surfaces are precision ground to exacting tolerances to ensure optimal gas efficiency. The same machining standards are used for the carrier rails providing a super smooth fit and function from the start. Specifications for Aero Precision AR15 5.56 PRO Series Bolt Carrier Group (BCG): Manufacturer: Aero Precision Color: Black Nitride Finish: Nitride Fabric/Material: 8620 Steel, 9310 Steel Gun Make: AR Platform Gun Model: AR-15 Condition: New Weight: 11.4 oz Bolt Material: 9310 Steel Carrier Material: 8620 Steel Country of Origin: USA Features of Aero Precision AR15 5.56 PRO Series Bolt Carrier Group BCG: Bolt: Machined from 9310 Steel with a flash nitride finish to ensure proper heat treatment. Shot peened and MPI Tested. Cam Pin: Index marked to ensure consistent installation, prolonging the service life of the bolt. Gas Key: Torqued to spec with grade 8 hex fasteners and properly staked. Firing Pin: Ground from 8640 steel and featuring a nitride finish. Carrier: Critical surfaces precision ground to exacting tolerances to optimize gas efficiency. Package Contents: Aero Precision AR15 5.56 PRO Series Bolt Carrier Group