The Rosco Bolt Carrier Group for 5.56/300 Blackout is a full auto style Mil-Spec bolt carrier group with properly staked gas key along with a Melonite finish for extended performance. Features a Shot Peened/ MP tested Matched bolt (with upgraded extractor) which is designed to lock up perfectly with their extensions for extreme accuracy. These BCG's are made to withstand Full-Auto rated fire and unforgiving use from the end user.
Features:
Features:
- Carrier Material: 8620 Steel
- Gas Key: 4130 Steel, attached with Grade 8 hardware, properly staked
- Cam Pin: Hardened 4340 Steel
- Firing Pin: 8740 Steel, Mil-Spec, Center-less ground & Hard Chrome coated Bolt Material: 9310, Properly Heat treated, MPI/HPT
- Extractor: 4140 Steel, Heat Treated, Shot Peened
- Ejector: S2-S7 Tool Steel, Shot Peened
- Melonite black BCGs ship with upgraded Sprinco Extractor Kit
