There's genuine, pure tung oil made from pressing the seed of the tung tree, and there's the various so-called "tung oils" often sold at hardware stores and the like. Most of the latter aren't really tung oils at all as they don't contain any of the tung tree oil. They are wiping varnishes that are made to mimic plant oils without having any plant oils in them. They are polyurethanes.
Wood stocks on commercial, mass produced rifles typically have a poly or lacquer finish. Paint stripper removes the poly, lacquer thinner removes the lacquer.
