AR-15 Nickel Boron Bolt Assembly - MPI C158
This back up AR15 Bolt Assembly is MPI inspected and comes plated in NiB coating which offers a high-lubricity for drastically reduced wear, maintenance, and oiling, and harder-than-chrome surface that will hold up to thousands of rounds of use. As an added benefit, it is also extremely easy to clean.
- Mil-Spec Carpenter 158® steel
- Coated Inside & Out With UCT EXO NiB
- Mil-Spec Extractor Spring, black extractor insert, Viton O-Ring
- Magnetic Particle Inspected (MPI)
- Caliber: .223 / 5.56 / 300 Blackout