When it comes to my ARC actions, I have dropped my Archimedes and Nukes into McMillan, Greyboe, McCrees, AG Composites, and a Stocky's, using SOL, Mesa Precision, Vudu, and Hawkins bottom metal. Fed fine from Magpul, MDT plastic and metal, Accurate mag, ARC mags, and another one I can't remember.
They all fed just fine with short action and long action. And, once I cut the feed lips back so that the cartridge was pushed up into the extractor by the shoulder of the cartridge below, I get consistent control round feeding. If you leave long feed lips, so that the angled shoulder of the cartridge second one is pushing the cartridge forward, you will never get control round feeding.
I ran Huber, Calvin Elite, TT Diamond, Special and Primary. They have all operated just fine. I could tweak the cocking pieces to time up the triggers a little better, but it is nothing so I don't bother.
I've run the Barloc, barrel nuts, and shouldered barrels. They all were easy to install and run great.
The Archimedes is growing on me, I might like it better than my Nuke. I wish I had done the Xylo preorder...