Original STG 1928 Complete Bolt Assembly with Extractor Assembly. This bolt is identical to the previous STG1928 bolt other than the NiB plating and the addition of the Headspace Stop Bar. It is compatible with all STG1928s setup that are able to take drums.
NiB One™ plating
This is an electroless NIB nickel-boron plating system that is comprised of boron, nickel, and other metals to produce a very hard, wear resistant surface with a low coefficient of friction.