Black powder could very well be the most versatile powder for shotgun loads.
In the book "Sporting guns and gunpowder" from 1897, a test is done between damascus and steel barrels:
https://archive.org/details/sportinggunsand00tomsgoog
"Fig. 3 shows the unbrazed Damascus barrel. With this the first indication of distress was seen after firing test No. 23, when the charge was 7 ½ Drs. of powder and 12oz. of shot; it was then somewhat rivelled and bent. In the next round the barrel commenced to bulge at 6in. from the breech; but it held on for six more trials, and collapsed at test No. 30, with 11 Drs. of powder and 12oz. of shot."
"Fig. 1 represents the remains of the unbrazed barrel of Siemens-Martin steel, which burst with test No. 40, when the charge used was 16 Drs. of powder and 12oz. of shot. This barrel first exhibited signs of distress with trial No. 26, when the charge was 9 Drs. of powder and 12oz. of shot, the tube then showing a slight bulge at 7in. from the breech, and being somewhat rivelled and bent near the muzzle; nevertheless, it underwent thirteen more tests before the actual fracture occurred."
More than 200 grains of black powder behind 12 ounces of shot in a damascus barrel
and twice that amount of powder in a steel barrel. It looks to me it would be physical impossible to cram enough black powder into any shotshell to harm the gun.