Quite apart from cutting loose the welds and pins used for dewatting, the Ross barrels are held into the receiver by just a couple turns of very large and very fast threads. The barrel is kept from unscrewing by a plug/wedge that is threaded into the underside of the front receiver ring. It's been years since I have done it, but if I recall correctly, that has to be removed in order to unscrew the barrel.

M