Yes I have removed the barrel from the receiver, the stock and fore end attach to the receiver via allen screws and the barrel is held in the receiver via allen screws also . The bolt locks-up in the barrel not the receiver on this model as you mention , I guess my question is can the existing barrel be salvaged to provide the barrel extension you speak of ? and can that extension be modified to the Savage system ? , since no one I know of except Border Barrels manufactures fitted and proofed barrels in cartridges other than stock Sauer replacement barrels . I mention the Savage system because of the possibility of regaining the option of multi caliber replacement barrels in configurations I want , not what Sauer provides .
The Sauer 200 and Savage systems are two completely different beasts.
Sauer uses a barrel extension (like the AR10 or AR15) where the bolt locks into. Head spacing is set by screwing the extension tightly onto the barrel and then reaming the chamber deeper until the bolt closes on the "GO" but not on the "NO GO" gauge. The barrel with the attached extension - let's call it barrel assembly - is then clamped in the receiver and can be changed easily to a different, previously head-spaced, barrel assembly.
Savage screws the barrel into the receiver and uses a counter nut to hold it in place. Barrels can be changed by by loosening the nut, un-threading the old barrel, screwing the new barrel in until the head space is OK, and re-tightening the nut.
All you need to put another barrel on a Sauer 200 (or SSG3000) is an extension, a barrel blank, and a competent smith.
If you cannot get a separate extension, you could try to get one off an old barrel assembly but it is most likely screwed on very tightly. I went this route to make custom barrels for my Lewis Machine MRP rifle after Karl Lewis refused to sell the extensions seperately. However, getting the extensions loose from used barrels was a bear. I had to cut into several barrels close to the extension shoulder with a thin parting tool to relieve the tension holding everything together.
PS: FN combined the screwed-on barrel extension with a counter nut on the SCAR. My guess is that they make the barrels with fully finished chamber in one process (i.e. hammer forging and chrome plating) and then screw the barrel to the extension, adjust the head space, and tighten the nut further down the assembly line. Similarly, one could try with some creative engineering to put a counter nut in front of the Sauer 200 extension. It would look strange but it would make it easier to re-use one extension for multiple barrels.
