Rainier Arms AR-15 5.56/.223 Precision Match Grade BCG Black Nitride Small

The Rainier Arms Precision Match Grade 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 Carrier SAE 8620 Heat Treated Nitride Bolt: 5.56/.223 Carpenter 158 Steel Shot Peened Heat Treated Nitride Extractor: Machined from bar Shot Peened Heat Treated Manganese Phosphate Sprinco M4/AR-15 Extra Power 5-Coil Extractor Spring: 5 coil design Optimal for 16" or shorter rifles For AR-15 BCG Polymer inserts Made from Chrome Silicon wire stock Heat treated, stress relieved, and cryogenically processed Extractor Retaining Pin: Precision Machined Precision ground to diameter Precision ground to length Heat Treated Firing Pin: Machined and then precision ground for accuracy Heat Treated Gas Key Bolt: Precision manufactured in house with extra deep knurling Grade 8 1200 degree lo