Found these videos and thought I would share for anyone who is curious how a bore is "lapped". This is very similar to how I "lap" a bore. CAUTION: Lapping can destroy a bore and is not needed on many barrels. Those of you who may be working with blanks and raw bores could find use in this. You don't want to try this on your new Cricket, Vulcan, Wildcat, ect. "Finish Lapping" or "polishing" with JB or Flitz might help but that depends on the degree in which the barrel maker finished that particular barrel.
https://www.youtube.com/watch?v=WM8xaaUaTTY
https://www.youtube.com/watch?v=IXzmlDT-yxE
https://www.youtube.com/watch?v=WM8xaaUaTTY
https://www.youtube.com/watch?v=IXzmlDT-yxE