Description Mil-Spec BCG Machined from 8620 Aircraft Quality Steel and heat treated to 60-61 RC Mil-Spec Chrome Lined Carrier Interior Mil- Spec Chrome Lined Gas Key Key Staked with Grade 8 Screws, per Mil-Spec Mil-Spec Carpenter 158® Bolt w/ Spring and Ejector Tool Steel Extractor w/ Spring and viton O-ring Mil-Spec Firing Pin w/ Chrome Finish Mil-Spec Cam Pin Full Auto Carrier (Backward compatible with all semi-auto rifles) 5.56 BCG Weight – 11.55 oz.
