The latest info I had read noted the Archimedes was changed to have an integral lug. So, you'd need to buy a conical washer to place ahead of the recoil lug for this to work on the Archimedes.
[/
Are you sure you aren’t thinking about the Defiance Tenacity? They just announced thst Change to it last week. This info is still on American Rifle Companies Website.
- Keyed recoil lug does not require pinning.
- Pin-less recoil lug is clocked by the scope rail.