Luth-AR AR-15 Complete Bolt Carrier Group 223 Rem

The bolt carrier group does the actual work in an AR, and Luth-AR sells this one assembled rather than as a bare carrier, so it goes into an upper without hunting down a bolt, a gas key and a handful of small parts to finish the job. The carrier is steel with a chrome lined bore, and the assembly comes with the carrier key, cam pin, firing pin and retaining pin already fitted.

Manganese phosphate is the military pattern finish, and there is a practical reason it stuck around: the porous surface holds oil, which is why a properly lubed phosphate group keeps cycling after a dry one starts to drag. Cut for 223 Rem and standard AR-15 uppers, it works as a replacement for a worn group or as the starting point for a build.