RISE Armament’s Nickel Boron Bolt Carrier Group is a perfect start to any custom AR-build, or as a solid upgrade to an existing rifle. It features a Nickel boron coating, a columnar-formed compound composed of about 95 percent nickel and 5 percent boron. This formation reduces the contact points between surfaces while simultaneously providing an additional level of hardness to the steel. The result is a natural lubricity and improved durability. When compared to the industry standard chrome coating, the nickel boron coating offers greater resistance to corrosion for a significantly longer service life.

Features:

• Unit weight: 11.6 oz.
• Individually MPI tested
• Bolt: 9310 MPI tested
• Carrier: 8620 tool steel heat treated and case hardened
• Gas key: tool steel - grade 8 hardened fasteners and staked properly
• Cam pin: 4140 steel
• Extractor: tool steel – shot peened