I have a Savage large shank barrel, 1.120. The threaded section of the barrel is about 1.3 inches long. For a number of reasons I need it to be about 1.5 inches long. Can I extend, cut, these threads by hand using a 1 1/8-20 UN die and 2 1/2 handle? I have access to them for free. Or is taking it to a gunsmith and using a lathe required? Any helpful advice would be greatly appreciated.