NBS AR-15 .223/5.56 Bolt Carrier Group – Phosphate - 51108

The NBS5.56 Bolt Carrier Group for AR-15 rifles is made from high quality materials with quality assurance measures like high pressure testing and magnetic particle inspecting. The bolt assembly is machined from Carpenter 158 tool steel and tested to ensure it can withstand thousands of high-pressure rounds. The Carrier assembly is machined from 8620 steel and the entire BCG is magnetic particle inspected to ensure every dimension is as precise at can be. The Manganese Phosphate coating on this AR-15 bolt carrier group will increase in lubricity as it absorbs oil and combines with the natural lubricity of carbon to ensure your rifle will run reliably. 

Features:

• Compatible with 5.56 NATO, .223, and .300 BLK
• M16 cut and full auto rated
• 8620 steel carrier
• Carpenter 158 tool steel bolt
• MPI and HPT
• Manganese Phosphate coating
• Properly staked gas key
• Chrome lined gas key and firing pin channel
• Shot peened bolt face
• Black O-ring extractor insert