Are you sure there's no serial number on the receiver? Look for the importer's stamp, by law they all must be id'd by importer. Earlier imports were allowed to be serialized on the barrel near the importers stamp, on later imports the ATF required a new serial number to be stamped onto the receiver itself, but the ATF serial number is most frequently in the same area as the importer stamp. Many are dot-matrix stamped, though some were hand-stamped with fully formed characters.
The legal serial probably won't match the serial on the barrel as stamped by the Russians.
If you really do not have a receiver serial number, I'd destroy the receiver before dismounting the barrel, and document the process. Maybe take a before picture with today's newspaper & date visible, then one with the destroyed receiver and tomorrow's newspaper, then finally one with the destroyed bits and removed barrel and a newspaper.
The legal serial probably won't match the serial on the barrel as stamped by the Russians.
If you really do not have a receiver serial number, I'd destroy the receiver before dismounting the barrel, and document the process. Maybe take a before picture with today's newspaper & date visible, then one with the destroyed receiver and tomorrow's newspaper, then finally one with the destroyed bits and removed barrel and a newspaper.
), it's most likely like SJ said, it came in before the ATF changed the serial number laws. A friend has a Finn that is like this, serial # is only on the barrel and no import marks, the # on the barrel is the rifles serial number and what he logged it as in his C&R book.
