I have to agree/concur with Casper and Roth.

The original type of M/S action remains the smoothest bolt action ever manufactured.

If the bore is 6.5 then it should be a 1903. I have a 1903 and 1908. My '03 has the same scope bases as the one you picture but, unfortunately I do not have the rings or scope.

If you dismount the barreled action from the stock the proof marks will be on the bottom of the barrel and action and more can be told about the rifle.