Rainier Arms AR-15 Precision Match Grade BCG - Nitride

The Rainier Arms Precision Match Grade Phosphate BCG - 5.56 Nitride is machined and finished to a higher standard to meet and exceed all Mil Spec. It is machined using the most precise equipment in the industry. The bolts are MPI/HP tested & Marked to give you ultimate confidence in your weapon system. Carrier: Full Auto CarrierSAE 8620Heat TreatedNitride Bolt: 5.56/.223Carpenter 158 SteelShot PeenedHeat TreatedNitride Extractor: Machined from barShot PeenedHeat TreatedMaganese PhosphateNitride Extractor Spring: Chrome Silicone for Longer LifeBlack Insert as per current Mil-Spec"O" Ring is high temp resistant dark brown Extractor Retaining Pin: Precision MachinedPrecision ground to diameterPrecision ground to lengthHeat Treated Firing Pin: Machined and then precision ground for accuracyHeat Treated Gas Key Bolt: Precision manufactured in house with extra deep knurlingGrade 81200 degree locking patch is factory applied to threads to help insure long lasting tightness Gas key: Hard Chrome lined gas tube as per Mil-SpecBolts installed to proper torqueStaking on both sides of both boltsNitride Cam Pin: Precision machinedHeat TreatedNitride Firing Pin Retaining Pin: Precision bentPrecision cut to lengthHeat Treated Gas Rings: Stainless Steel per Mil-Spec Ejector: Precision machinedHeat Treated Ejector Spring: Chrome SiliconePrecision ground ends Ejector Retaining Pin: Precision cut to lengthHard Chrome Plated   Limited Lifetime Warranty We are so confident in our Rainier Arms BCG we offer them with a limited lifetime warranty. So if at anytime your Rainier Arms BCG breaks on your during normal use(Intentional abuse & Gas Key wear not included) we will replace it.