You didn't explain what you are trying to accomplish. I guess you might want to remove some pitting (light pitting will not hurt anything except appearance, and will not get any worse with regular cleaning of bores)
If you are doing this for choke reasons, I would be careful of wall thickness.
Could you use an adjustable reamer, the only thing you would have to do is drill and tap a hole in the end and use a threaded rod, and double-nut it.
If your bores are .775 this would work.
http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=334-1112&PMPXNO=945451Good luck and let us know how you make out.