In one of the gun magazines not too long ago, among others, they blew up an old damascus Parker, I think it was, to test how much the damascus barrels could take. It held up under crazy pressures and showed signs of distress before heavier charges finally actually blew it up.
If all the welds in a damascus barrel were properly made originally and none have eroded/corroded since, I wouldn't fear to shoot smokeless trap loads from it if it were mine, though I'd probably use black powder because I just like it. The advice Gary gave about having it magnafluxed is good, and if there's any other way to be sure there isn't degradation in those welds, I don't know about it.
Steve
