I use two different Damascus 12 ga shot guns for bird hunting.
Try a smokeless load in yours if you want. I load the following....
Federal plastic hull w/ paper base wad. Fed 209A primer. 23.5 grains SR 7625. Wad is Claybuster Windjammer style #CB 4100-12-B, made by C & D Special Products, 309 Sequoya Drive Hopkinsville KY 42240
Shot charge is 7/8 to 1 ounce of # 7 1/2. fold crimp. Pressure is about 4800 psi. Normally smokeless is a NO - NO in Damascus double shotguns. The steel is brittle and will shatter right at the handguard with most modern loads. Makes you lose a few fingers on the non shooting hand. Check the bore of your gun to make sure there are no rust pits from the old black powder shells. I've used the above load for MANY years and still have all my fingers.