Think of this as a side bar to this thread:
In the original post David wrote, "I know sandpaper (glass paper) is historic but I can't imagine a gunsmith on the frontier had access to it."
The VAST majority of gun making was not done "on the frontier." Gunshops were in cities and small towns along the trade routes to the frontier. The same trade network that supplied imported locks, rasps, files, crucibles, lead and powder could deliver whatever pumice, emery, or abrasive paper a smith felt he needed.
What few gunsmiths worked on the actual frontier were busy repairing guns with an occasional restocking or assembly of a components gun thrown in.
Gary