Got the Springfield Omega 10mm. The entire slide assembly is Peters Stahl. In addition to oktagon's post, the early models had duel extractors, the left one having a little less grab than the right one. This is supposed to allow it to relesae sooner than the right one causing the case to fly off to the right as a normal 1911 would when the casing hit the ejector. This didn't always work 100% of the time and the shooter (which I can attest from my own experience) will get bonked in the forehead with an empty (or down the front of a loose shirt, ouch).
The reason for hte duel extractors is that they spring inward far enough to allow caliber swaps with just a barrel/spring/mag change as all of the chambers are externally identical in dimensions and fit in the same breachface.
Later models had one extractor that could be adjusted inward/outward by a hexbolt from the left side. The recoil spring plug also had modifications too to ease (or in some opinions, complicate) removal.
The lockup is similar to the current SIGs and HKs, i.e., modified Browning, which I think is considerably better than the link/pin setup.
The frame is a standard 1911.
I could have sworn that when Springfield stopped impotring the slide assemblies and completing the guns that McMillan picked it up for a while as the 'Wolverine' line.
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- Ron V.