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 parts include:

• EXO Coated Bolt - Case Hardened, Shot Peened and MPI (Magnetic Particle Inspected)
• EXO Coated Extractor (fully assembled)
• All other components are Mil-Spec