Thanks Bogey. Yep Damascus twist barrels. Only feed it on FG blackpowder, bit slower burn and do not over pack the charge. Run at between 25 -30 grains by volume. Gets that big old ball moving at moderate pace without too much stress on the action.Gunsmith inspected the bores and welds and all aok which is amazing considering its history and miles it has travelled.
It only comes out to play a few times a year.
Think it's had it's working life in hotter climes.