The Phase 5 M16 bolt carrier group is a complete AR-15 BCG built on a full-mass M16-profile (full-auto) carrier and chambered for 5.56 NATO / .223 Remington. The heavier M16 carrier is legal in semi-automatic rifles and adds dwell mass for more reliable cycling, especially in carbine-length gas systems and suppressed builds.

Features:

• Complete AR-15 bolt carrier group — fully assembled, ready to install
• M16-profile (full-auto) carrier — legal in semi-auto AR rifles
• 5.56 NATO / .223 Remington — drop-in for mil-spec AR-15 uppers
• Bolt machined from Carpenter 158 steel — the standard mil-spec bolt alloy
• MPI (magnetic particle inspected) and HPT (high-pressure tested) — defect screening on every bolt
• Black nitride finish in and out — easier cleaning than phosphate, better corrosion resistance
• Properly staked gas key with Grade 8 fasteners

Build pairing: drops into any mil-spec AR-15 upper. Pair with a quality charging handle and an H1 or H2 buffer for carbine-length gas systems running 5.56 NATO. Mid-length gas systems can typically run a standard carbine buffer.

Inspect the bolt and lugs for damage before first use. Lube the cam pin, bolt body, and gas rings, then cycle by hand to confirm free movement. Run a 100-round break-in with quality 5.56 brass before relying on the BCG for duty use.