Remage is a combination of the words Remington and Savage. Take a Remington action (or clone) and instead of using a lathe to set headspace, you set it up like a Savage with a barrel nut (jamnut). It allows you to put a go gauge in the chamber, then tighten down the barrel till it bumps it, then tighten up the barrel nut. Allowing easy barrel changes and easy headspace adjustment. Criterion is one of the mfrs that will chamber a barrel blank, thread it to go into a Remington action and accept a barrel nut