One Horse OH-UBCO1 M16 Bolt Carrier Group 5.56/.300 Blackout Nitride AR-15

The One Horse OH-UBCO1 M16 Bolt Carrier Group is a duty-grade nitride BCG purpose-built for the AR-15/M16 platform and engineered to run 5.56 NATO, .223 Remington, and .300 Blackout - a versatile drop-in for general-purpose rifles, defensive builds, and .300 BLK suppressed hosts.

The carrier is machined from 8620 steel and paired with a 9310 steel bolt that is MPI (magnetic particle inspected) for verified material integrity. A full salt bath nitride finish hardens the working surfaces, reduces friction for smoother and more consistent cycling, and seals the steel against corrosion - extending service life in dirty or suppressed environments. The Grade 8 gas key is properly staked to the carrier so it stays locked in place under hard use.

Profiled in the M16 configuration for full compatibility with both semi-auto AR-15 uppers and M16-pattern builds, this bolt carrier group drops into any standard AR-15 upper receiver and is made in the USA by One Horse.