Another gun shop 'expert'. Found this on the internet, but the original source was not sited, nor the date. Anybody know this confused fella?

http://www.freerepublic.com/focus/bloggers/3018315/replies?c=18
Damascus barrels were actually superior barrels when new than many cold rolled welded barrels and hammered steel barrels. BUT, and it is a big but, over time the discontinuities in the Damascus barrel forging technique allows for internal corrosion to form in the hammered wire forging that that forms the Damascus barrels. This corrosion between the mechanical/welded/pressure joining of the metals that are at the core of all damascene metals is unavoidable, weakening the mechanical welded heat bonding because oxygen is incorporated in the joint by its very nature. . . starting the formation of rust at the creation of the barrel. With age, all damascene barrels LOSE considerable strength.
Barrels in that period were ALL proof tested with black powders that were far less pressure producing and slower burning than modern faster burning, higher pressure producing smokeless shotgun powders. Now add the corrosive nature of black powder and the even greater corrosiveness of the fulminate of mercury primers used during the useful life of most of these damascene barrels and its effects on accelerating the corrosion between the domains of the metal in those much more porous barrels. Shooting shotguns with Damascus barrels with modern loads is NEVER advised.
I am past manager of the Olde Sacramento Armoury and I was the appraiser and buyer of used and antique firearms for Simms Hardware (Sacramento) Gun Department — which was named #1 Gun Dealer in the United States in 1971. . . and was a qualified expert in the California Courts on the identification and values of Antique firearms back in the 70s. We labeled every damascene barreled shotgun a wall hanger, a non-shooting relic and instructed all sales people to instruct buyers that they were never to try shooting them as they were considered unsafe. We had several "educational pieces" on hand with blown chambers to show them what would happen if they tried. A couple of those looked brand new. . . and were made by some of those "top names" in gun making from London and New York. They still blew.


https://sites.google.com/a/damascusknowledge.com/www/home