FWIW, the problem with smokeless powder in Damascus barrels is not so much the chamber pressure, but the burning curve. Smokeless powder burns slower than black powder ("progressive burning") and maintains pressure further out in the barrel. Because BP pressure drops off quickly, most BP barrels thin down just before the end of the forearm, allowing the gun to be lighter at the front end and with more "whip" as the old timers used to say.
So smokeless powder pressures are still high at the point the barrels become thin, which is just where the shooter's off hand is usually placed. When the barrel lets go, it usually takes a couple of fingers along for the ride.
Add that to the fact that no matter how strong a Damascus barrel might have been when it was new (those who claim there is no danger always cite the fact that the barrels passed proof), years of corrosion eating into the welds will have weakened the barrels. I have sectioned a few old Damascus guns and found the interiors to be like dirty lace, in spite of nice exteriors and bores that looked clean and shiny.
Jim