one would assume that it was shortened from the rear and rethreaded
yeah and a bunch at that, I would think over .5" would have to be cutt off the shank of the barrel for a 308 reamer to clean up a 270 win chamber, from the looks of the pics unless the stock has been changed I would expect to see some gapping in the barrel channel, which I don't. I would double check to see if that is really what you have.
