This is from a manufacturer that does them for major brands held secret by NDA’s.
Material Carrier: 8620 Steel
Bolt material: 9310 Steel
Gas Key: 17-4 Stainless Steel equivalent of stainless steel to resist the chemicals in the exhaust gases of the semi-automatic system
Extractor: S-7 Shock resistant tool steel premium tool steel designed for shock resistance and strength. (Everyone else is using 4140)
Firing Pin: 17-4 Stainless Steel
Cam Pin: 420 Stainless Steel
Ejector: 420 Stainless Steel
Reliability Post & FA O-Ring: VITON rubber, our own mold (competition is a lesser material). This
resists the caustic gases for LONG TERM reliability and is super crucial.
Product Coating: Black Nitride / QPQ
Product Summary & Production Advantages
We use Stainless Steel for the entire bolt carrier group, which is a stronger material and one that is naturally resistant to chemicals, corrosives, and long-term corrosion.
Our hardness is MILSPEC to depth and a “white layer” of 72 RHC for .0002” from the nitride process. We have been manufacturing this part for over seven years and have refined it to a full mature product line, with quality control CMM processes in place at all points, as well as coating knowledge that new machine shops to the recent gun rush will not understand and be prepared for. It is because of this longstanding experience with running these specific parts, and the fact that we make all the small parts needed for production in-house, that makes our supply chain so reliable and stable.