Thanks for your replies. Forgot to mention that the gun has Damascus barrels and external hammers. Some time this spring, will try it with light black powder loads with the gun strapped to the firing bench and pulling the the triggers with a long string.
But, with my usual BP loads, the wads will be fiber. Should I borrow some plastic wads and use those in my test reloads rather than the fiber? The chambers are either 2 3/4 or 3 in, so it was (as far as I can tell) made to fire smokeless loads.
How and where could the barrels be honed out?
Again, happy to post some photos but don't know how to post to this forum.