This fully assembled and NiB coated (5.56/.223) bolt assembly is compatible with most mil spec AR15, M16, M4 Carriers. EXO Nickel Boron provides permanent dry lubricity; increased wear and corrosion resistance. By reducing friction this bolt assembly will make for easy cleanup and improve the performance of your rifle.

• Nickel Boron treated
• Extreme durability
• Dry lubricity
• Corrosion resistant