Rosco Manufacturing Bolt Carrier Group for AR-15 – 5.56 NATO/.300 Blackout, Melonite Finish (ROS-BCG-001)

• Bolt carrier group designed for AR-15 rifles chambered in 556NATO and 300 Blackout
• 8620 steel carrier with Melonite finish providing durability and corrosion resistance under heavy firing schedules
• Properly staked 4130 steel gas key secured using Grade 8 hardware for reliable gas system operation
• 9310 steel bolt heat treated and MPI HPT tested for strength and consistent lockup performance
• Includes hardened 4340 cam pin and 8740 steel firing pin with hard chrome coating
• Full auto rated construction built to withstand sustained fire and demanding operational use conditions

The Rosco Manufacturing Bolt Carrier Group 556NATO/300 Blackout AR-15 Melonite Finish Black is a bolt carrier group designed for cycling and operation in AR-15 platforms. This bolt carrier group is compatible with 5.56 NATO and 300 Blackout calibers and uses a melonite finish for surface treatment.

The Rosco Manufacturing bolt carrier group is constructed with an 8620 steel carrier and a 9310 steel bolt that is MPI and HPT tested. It includes a 4130 steel gas key secured with Grade 8 hardware and a properly staked interface, along with a hardened 4340 cam pin and 8740 steel firing pin with chrome coating. The extractor uses 4340 steel and the ejector uses S7 tool steel. This model is used for rifle assembly and maintenance in AR-15 configurations requiring mil-spec components.