Another point of view: If you can find a copy, take a look at the Autumn 2009 issue of The Double Gun Journal. Look for the article "Finding Out for Myself part XVI by Sherman Bell.
Bell took six old "bargain basement when they were new" damascus barreled SXSs and subjected them to torture testing by firing "proof" loads through their pitted, dented barrels.
Results: NOT ONE of these barrels failed. Six cheapo guns, 54 high pressure proof loads and no failures. In fact, there were no dimensional changes at all to any of the barrels.
Pete