CMMG Bolt Carrier Group MK3 .308

CMMG Mil-Spec MK3 .308 Complete Bolt Carrier Group. The bolt is made from 9310 Steel with a Phosphate Finish. The carrier is machined from 8620 Steel, Chrome Lined and has a Phosphate Finish. The extractor is made from 4140 Steel with a Phosphate Finish.