I would not fire a damascus-barreled gun without having it checked and approved by a competent gunsmith (NOT the guy with a key to the gun case at Walmart!). It is possible that a gun of this age would have been proofed for smokeless powder and have 2 3/4" chambers, but it is more likely to be made for 2 1/2" black powder shells. Of course, you can have barrels custom-made, but why would you want to spend a couple thousand dollars on a gun worth $200 or less?
Yes, they are safe to shoot, but only if:
I have been shooting them for years with smokeless powder with lite loads. Have it checked out by a good gunsmith to make sure the inside of the action is in good working order, some of the old ones will double when fired.
I would third the recommendation to have it checked. Absence of visible pitting is not necessarily a good indicator of structural integrity. Older damascus may corrode in between the layers and there is no way to see that just by eyballing it.
Some are, some aren't. If it has Damascus or Laminated steel barrels, do not shoot it. They were never intended for modern powder. Fluid steel or later production barrels may be safe, but if there is rust, dents, or other signs of high wear do not try it until after it has been inspected by a competent gunsmith.
As a general rule, NO, NO, NO!!!!
Some did, but not all.
They are still being made.
The time of the First World War pretty much ended the importation of Damascus barrels. US manufacture started petering out in the 1890's.
The use of damascus barrels on guns began to decrease pretty rapidly after 1900, although they were still fairly common up until the start of WWI. If you have a breech loading gun with damascus barrels it will probably date from 1875 - 1910. Most damascus barrels on U.S. guns seem to have actually made in Belgium. There is a lot of debate as to whether any damascus barrels for shotguns were actually made in the U.S. It seems likely there may have been small numbers produced in the U.S. However, Belgium had a large gunmaking trade at the time, with a lot of barrel makers specializing in damascus barrels, so it was generallly cheaper to import them than to make them.
Most old Damascus barrels cannot hold the pressures of modern smokeless loads. I doubt that you will find any black powder loads for that type of barrel. Hang it on the wall and admire it.
no . riverside was mainly produced after 1914, using fluid steel barrels.
I'm not aware of any shotguns ever made with two barrels twisted together. If you are refering to "Damascus Twist" barrels, you need to learn a lot more about guns before buying one. Here is some information for you...please note the part about it not being safe to fire a Damascus barrel with modern powder. Picture an onion after a fire cracker went off inside it. http://www.hallowellco.com/damascus_twist_barrels.htm
no not all twist barrells
DO NOT FIRE WITH MODERN AMMO!!!!!!!!!!!!!!! MUST be checked out by a gunsmith.