Occasionally I hunt with an Ithaca Flues 20ga grade 1-1/2 damascus double. My load is 2 dram of black powder and 3/4 oz of shot in a plastic case with fiber wads. I only use black powder only as the gun is pretty light in weight and some small frames have been known to crack. The barrels are 28" and choked cylinder-(right) and full-(left)and chambers are 2-3/4". It does have the Nitro powder proved stamped on the bottom of the lug.

Jack K