sinman just to clarify I was going to have a local gunsmith chamber and thread the barrel. I don't know the order it is done- chamber/thread or thread/chamber. Also the blank will have to be cut to length and crowned. Since I am going to have my gunsmith do most the work does it make any sense to have Pac Nor thread it first for me. I do not know as I said the order these procedures are done. It does seem I have allowed enough extra diameter to the barrel to err on the side of caution.