Nickel boron coated for lubricity and wear resistance advantages over regular nitride coatings. Also helps with carbon cleanup.

Machined to exact mil-spec dimensions. Heat treated, shot peened and relief cut.

Bolt Features:

• Carpenter 158 steel
• Heat treated
• Shot peened
• NiB coated
• MPI tested

Bolt Carrier Features:

• 8620 steel
• NiB coated
• NiB coated bore
• Full auto M-16 style/full mass