Noveske Bolt Carrier Group Features The Noveske Bolt Carrier Group is finished with a DLC exterior coating that improves wear resistance and keeps the carrier running smoothly cycle after cycle. The mil-spec bolt assembly is machined from 158 steel for the durability that hard use and sustained fire demand. A chrome lined bore adds corrosion resistance and makes fouling easier to clear during routine maintenance. Machined to USGI specifications from aircraft grade 8620 steel the carrier maintains the dimensional tolerances needed for dependable function in M16 M4 and AR-15 style receivers. This carrier ships complete with a mil-spec gas key that is both chrome lined and heat treated protecting against the heat and pressure of repeated cycling at the gas port. The DLC coating also lowers the carrier s coefficient of friction which helps keep the action running cleaner between cleanings. Compatibility with 5.56 NATO and .300 AAC Blackout chamberings makes this a versatile choice for builders running either cartridge through the same platform. Shooters upgrading a worn or soft factory carrier will find this a straightforward mil-spec correct replacement for their build. Noveske Bolt Carrier Group Specifications Manufacturer: Noveske Model: Bolt Carrier Group Type: Bolt Carrier Group Color: Black Finish: DLC Compatible Hosts: M16/M4/AR-15 Style Receivers Caliber: 5.56 Available At: GrabAGun