I bought a bottle of 100% pure tung oil from a company named "The Real Milk Paint Co." Their website is
www.realmilkpaint.com
It is the real thing, not too pricy and a 8oz bottle will probably last you a lifetime.
I used it on 2 gunsstocks so far and hardly dented the amount in the bottle. It gives a great "oil" finish and drys overnight or faster.