This bolt is for use in 458 SOCOM, 375 SOCOM, and 450 Bushmaster uppers.
Installs in standard 5.56 bolt carrier with standard 5.56 firing pin, cam pin, and firing pin retaining pin.
Bolt includes gas rings, extractor, and ejector. Extractor and Ejector are specific to the big bore calibers. They are not 5.56 parts.