Tracking all about the BARLOC portion, thank you.
I'm really getting at if I have to get a new barrel for the Archimedes or not, since I am swapping the Nucleus for my new Archimedes in my match gun. I have a shouldered prefit barrel from PVA for a Nucleus with BARLOC. If the Archimedes doesn't have the beveled recoil lug of the Nucleus will the headspace remain the same if you use the beveled washer on each end of the Barloc? It doesn't appear so according to the BARLOC pdf (images "without lug" and "with lug") on the ARC site.
I think it will still work but I'd call them to make sure.