Midwest Industries AR-15 5.56 Black Nitride BCG

The Midwest Industries AR-15 5.56 Black Nitride BCG is a complete bolt carrier group for compatible AR-15 rifles chambered around the .223/5.56 family. Midwest Industries specifies a C158 Carpenter steel bolt and a black nitride surface treatment for the assembly. The black finish matches the conventional appearance of the AR upper receiver while providing the listed nitride treatment across the carrier group.

A bolt carrier group is a core operating component, so compatibility should be verified against the exact upper receiver, caliber, and gas-system setup before installation. The C158 bolt material is the key confirmed material specification supplied for this model, while the carrier is sold as a complete 5.56/AR-15 assembly. Installation and headspace-related checks should be handled according to the firearm and component manufacturers' guidance.

This BCG is intended for a builder replacing or completing the moving assembly inside a compatible AR-15 upper. It should be compared by caliber support, bolt material, surface treatment, and compatibility rather than by appearance alone. Browse more gun parts and accessories for AR components and replacement parts.

• 5.56/.223 AR-15 configuration
• C158 Carpenter steel bolt
• Black nitride finish
• Complete bolt carrier group