The Aero Precision 5.56 Bolt Carrier Group (Black Nitride) is a premium, American-made BCG engineered for reliability and long service life in AR-15 builds. Built around a M16-cut 8620 steel carrier and a 9310 tool-steel bolt, this BCG is shot-peened, HPT-tested, and MPI-marked for consistent strength and durability. A Black Nitride finish delivers low friction and easier maintenance, while the carrier's forward-assist serrations and a properly staked gas key ensure dependable performance under heavy use.Whether you're building a duty rifle or tuning a precision AR, this Aero Precision BCG delivers the quality features shooters expect - and ships from a trusted supplier. Pick up your Aero Precision BCG at AR-15 Discounts for fast checkout and competitive pricing.Key Features M16-cut carrier for proven compatibility and function Machined from 8620 steel (carrier) Forward-assist serrations on the carrier for positive engagement Black Nitride finish - lower friction, reduced need for lubrication and easier cleaning Properly staked gas key for secure, reliable operation Bolt machined from 9310 tool steel for high strength Shot-peened, HPT tested and MPI marked for durability and safety Black o-ring extractor insert for improved extraction consistency