Rosco Manufacturing Bolt Carrier Group (Nitride) – 5.56 / 300 BLK


In stock

SKU: ROS-BCG-001 UPC: 181969500821

Product Description

These 5.56 / 300 BLK Bolt Carrier Groups are Melonited, Full-Auto rated, are properly staked, and the bolts are Matched to the barrel. Check your local laws and regulations on ownership guidelines.

Our Rosco Melonited Bolt Carrier Groups are designed to meet the modern-day carbine shooters’ requirements. We have also balanced input from our consumers and military end users in order to bring you the product you need, not just the one we want to sell you.

All Rosco BCGs are to MIL Specification and have a properly staked gas key along with a Melonite coating for extended performance. They also feature a Shot Peened/ MP tested Matched bolt (with an upgraded extractor) which is designed to lock up perfectly with our extensions for extreme accuracy. These BCGs are made to withstand Full-Auto rated fire and unforgiving use from the end user.

  • Carrier Material: 8620 Steel
  • Gas Key: 4130 Steel, attached with Grade 8 hardware, properly staked
  • Cam Pin: Hardened 4340
  • Firing Pin: 8740 Steel, Mil-Spec, Center-less ground & Hard Chrome coated
  • Bolt Material: 9310, Properly Heat treated, MPI/HPT
  • Extractor: 4340 Steel
  • Ejector: S7 Tool Steel

Additional Information

  • Weight 0.7875 lbs
  • Dimensions 8 × 1.25 × 1.25 in




Technical Information

Caliber 5.56 NATO / .223 Remington , .300 AAC Blackout
Finish Melonite , Nitride
Material 8620 Steel , 9310 Steel
Color / Pattern

Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit