Toolcraft 7.62A-39 Bolt Carrier Group is a Full Auto BCG, manufactured using a 9310 steel bolt and an 8620 steel carrier. Together they make up one of the most popular and well-built bolt carrier groups on the market.What's more, Arm or Ally is proud to add Toolcraft products to our fantastic lineup of reputable manufacturers. Because of this, we can provide our customers with the best available AR parts at affordable prices.Toolcraft is a major OEM manufacturer for the U.S. Military and many other rifle manufacturers. Forget the fancy logo at a $75 premium, and have confidence it's 100% made in the USA, North Carolina. If ever a problem, simply call Toolcraft, and they will take excellent care of you with their no questions asked Lifetime Warranty.Lifetime Warranty - Toolcraft BCG carry a lifetime, no questions asked, warranty. Simply puta | Should any Toolcraft product fail, return it to them for a brand new replacement.Carrier SpecificationsMaterial: 8620 SteelType: M16 Full Auto (Preferred for most AR-15 builds)Gas Key Material: 4130 Steel; Grade 8 Gas Key ScrewsCoating: Black NitrideBolt SpecificationsBolt Material: 9310 Steel | Shot PeenedExtractor Material: 4140 SteelCaliber: 7.62A-39Bolt Face Depth: .125 (measured face to end)Mil-Spec O-Ring Mil-Spec Gas Rings (3)Cam Pin Material: 8620 SteelFiring Pin Material: 416 Stainless SteelOther: MPI Inspected