Marrakai,

Three wonderful catches. You must be living right!!

I have hand lapped several single shot rifles with somewhat rough bores and able to smooth them up to shoot lead bullets. I used an expandable lap and fine valve grinding compound and initially worked on the rough areas and then later the entire bore. One thing that is important (to me) was to use a thick rod centered using a cartridge case of rod guide to prevent the rod from dragging against the bore.