Have you tried to clean the bore with JB paste to smooth it out? http://www.frfrogspad.com/homemade.htm
Bore Paste
An excellent bore polishing paste that works as well as JB's can be made from equal parts of BonAmi™, paste wax (like Johnson & Johnson or Butchers), and light oil. The BonAmi is the "doesn't scratch" product. Regular abrasive cleansers may be too harsh for use in a bore.
put some one a patch and run it through the bore work it in and then run solvent patches down the bbl. After a few reps of this you should feel it smooth out.