Alex Pro Firearms (APF) has been in business since 1976 crafting highly precise components. APF has taken their line of precision AR components and added a Nickel Boron coating to provide increased lubricity and much greater wear resistance than standard finishes. The APF Nickel Boron BCG is heat treated, shot peened, and machined to mil spec standards. If you are looking for a high quality BCG that will provide years of abuse, this nickel boron BCG is the perfect upgrade to your firearm. FeaturesShot peened, nickel boron plated, 9310 steel BoltNickel boron plated, full auto, SE 8620 steel CarrierShot peened, nickel boron plated, CNC machined ExtractorPrecision ground, Swiss machined Firing pinChrome lined, nickel boron plated, CNC machined Gas KeySwiss machined, nickel boron plated Cam PinHeat treated componentsMachined to mil-spec standards