LBE Unlimited 5.56 Bolt Carrier Group – Nickel Boron Finish

The LBE Unlimited 5.56 Bolt Carrier Group delivers reliable cycling for AR-15 platform rifles. This replacement or spare BCG is machined to mil-spec dimensions for drop-in compatibility with standard AR-15 uppers chambered in 5.56 NATO and .223 Remington. The nickel boron finish provides enhanced lubricity and corrosion resistance compared to standard phosphate coatings, reducing friction during operation and simplifying cleaning after extended firing sessions.

The bolt carrier is machined from 8620 steel with a nickel boron coating, while the bolt is made from 9310 steel for strength in the locking lugs. The finish's self-lubricating properties mean less oil is required for reliable function. Installation is straightforward drop-in for anyone familiar with AR-15 field stripping—no gunsmithing required. The BCG includes a fully assembled carrier, bolt, cam pin, firing pin, and firing pin retaining pin.

• Part Type: Bolt Carrier Group
• Compatible Firearms: AR-15, 5.56 NATO, .223 Remington
• Carrier Material: 8620 Steel
• Bolt Material: 9310 Steel
• Finish: Nickel Boron (NiB)
• Installation: Drop-In
• Includes: Carrier, Bolt, Cam Pin, Firing Pin, Firing Pin Retaining Pin