Sons of Liberty Gun Works AR-15 Phosphate Bolt Carrier Group - SOLGWBCG556

Sons of Liberty Gun Works Bolt Carrier GroupWe look at the bolt carrier group as the heart of the gun. If the gas port is the lungs, then the bolt carrier group is the heart. It's what drives the entire gun. If you look at the AR platform's cycle of operations, everything happens around the bolt carrier group. Locking, unlocking, extracting, ejectinga |all of it begins with the bolt carrier group.The Sons of Liberty Gun Works Bolt Carrier Group features an M16 profile and is tested to ensure a lifetime of reliability.Bolt:Precision machined from Carpenter Technology No. 158 alloy,Heat treated per mil-spec,Shot peened per ASTM B851/SAE AMS2430S,Vibratory tumbledIndividual high pressure/proof (HP)Full Auto test fired as an assemblyIndividual magnetic particle inspection ASTM E1444/E1444M (MP)Markings deep laser engraved (SP=Shot Peened, HP=High Pressure Tested, MP=Magnetic Particle Inspection.)Extractor:Precision machined from 4340 tool steel alloy per SAE AMS6415T/AMS6484D (vs 4140),Heat treatedShot peen per ASTM B851/SAE AMS2430S.Extractor Retaining Pin:Precision machined and ground S7 Tool SteelHeat treated per ASTM A681-08Shot peened per mil-spec printManganese phosphateExtractor Spring:Tactical Springs/Sprinco 5 coil, ASTM Grade A401 Chrome Silicon wire stockHeat treatedStress relieved, Molybdenum-Disulfide infusedCryogenic processed (all post winding)Mil-spec black insert/synthetic elastomer extractor buffer (nitrile-butadiene, shore hardness 80+/-5 durometer per MIL-PRF-6855)Ejector:S7 Tool SteelHeat treated per ASTM A681-08Shot peened per Mil-SpecManganese phosphateEjector Spring:Heat treatedMil SpecGas Rings:Standard stainless steel per Mil-Spec X3Carrier:Machined from AISI 8620 aircraft qualty alloy per ASTM A108/A322-13Full auto profileHeat treatedCarburized/strain relieved, hard chrome borePrecision ground gas key interfaceSons of Liberty Battle Flag logo deep laser engravedManganese phosphateGas Key: Machined from 4130 chromoly steel alloy per ASTM A108/A322-13Heat treated, hard chrome internalManganese phosphatePermatex sealedGrade 8 hex screws torqued and staked all per mil-specCam Pin:Precision machined 4340 chromoly steel alloy per SAE AMS6415T/AMS6484DHeat treated/processed per mil-specManganese phosphateSolid film lubricant applied and cured per mil-specFiring Pin: Precision machined 8640 steel alloyHeat treated/processed per mil-specHard chrome plateFiring Pin Retaining Pin:Precision machined from 1038 carbon steelHeat treated/processed per mil-specManganese phosphate