Originally Posted by
Camp10
I dont know if it would work and I doubt I would try it but there are companies that make barrel inserts for shotguns. You may be able to slide these into the existing barrels and then use 20 ga, 28 ga or even .410. I've seen these in both a short version that only sized the chamber and others that are full sleaves. Again, I dont know if it will work or if it is safe for an old damascus gun but if you absolutely have to shoot the old gun, it might be an option to discuss with a gunsmith.