FailZero 5.56 Full Auto BCG Black

This FailZero bolt carrier group (BCG) ships fully assembled and is designed to drop into most mil-spec M16, M4, or AR-15 upper receivers. Critical components are treated with EXO Nickel Boron to provide durable dry lubricity, lower friction, and improved wear and corrosion resistance. The carrier is finished with a black topcoat while treated internal parts simplify maintenance and reduce the need for additional lubrication.

Key Specifications

• The product type is Bolt Carrier Group (BCG).
• Caliber compatibility is 5.56/.223.
• The finish/coating is EXO Nickel Boron treated with a black topcoat.
• The primary material is steel.
• The model designation is M16/M4.
• The configuration is full-auto BCG.
• Included components are bolt, extractor, carrier, cam pin, carrier key, firing pin.
• Intended installation is drop-in for most mil-spec M16/M4/AR-15 uppers.
• Dimensions are 1.65 x 3.75 x 10.30.

Engineered for dependable operation and easier maintenance, this FailZero BCG pairs robust steel construction with low-friction EXO Nickel Boron treatment to support extended service life and simplified cleaning routines. Its drop-in compatibility and fully assembled configuration make it a practical upgrade for owners seeking durable, consistent performance without unnecessary complication.