What exactly are the steps in replacing a barrel in a rifle? I bought an Arisaka in 7.7 and am thinking about maybe turning it into a 22-250. I figure case dimensions are close enough for it to feed so the major change will be a barrel, am I right? What should it cost about to get this done by a gunsmith (barrel included) any guesses? Or can I buy a ready threaded barrel and do this myself? I don't have anyone who knows how to cut threads on a lathe though.