AR-10 Bolt Assembly LR-308 Nickel Boron - DPMS Gen 1 Compatible.

AR10/ LR308 Bolt Assembly, Nickel Boron Finish.
  Replaces your factory bolt assembly and fits into your Bolt Carrier. Compatible with all AR10/LR308 DPMS Gen 1 specs but made better with superior materials and production processes. Our bolts are made with milspec C-158 steel. Each bolt is shot peened and treated prior to being plated with Nickel Boron for the ultimate in slick surfaces and reliable function.
  When to Replace Your Bolt Assembly: We recommend replacing the Bolt Assembly whenever you replace your barrel. An AR10 bolt head and barrel will have a certain amount of wear-in between them. So, it just makes sense to use a new bolt with a new barrel.