A B Arms A*B Pro 5.56mm Bolt Assembly - Nickel Boron Coated
Bolt
9310 Steel
Heat treated per Mil-Spec Requirements
Shot Peened per Mil-Spec Requirements
MPI Tested Material
Nickel Boron Coated per Mil-Spec Requirements
Extractor
Aircraft Quality E4140 Steel
Heat treated per Mil-Spec Requirements
Shot Peened per Mil-Spec Requirements
Nickel Boron Coated per Mil-Spec Requirements