Here is how the barrel Damascas was made. On twist steel, they were often horseshoe nails mixed with cast iron. They were welded and then wrapped around a barrel mandrel and edge welded. Laminated was more complex with many variations. However, a common method was to weld the same as above then twist it around itself before wrapping around a mandrel and edge welding. This gave the advantage of making a very small area of bad weld if there were an area of bad weld. That way, no blown barrels. The true barrel Damascas was even more involved. They started with 1/4"-3/8" wide strips of iron and steel and welded usually 3-5 of these into a flat, long bar. They then took 3-5 of these and alternately twisted them right and left handed. These were then edge welded and wrapped around a mandrel and edge welded again. This, again, made any poor weld a spot affair that would not effect barrel strength.
We have all heard of the danger of old Damascas barrels. This was a lie perpetrated on the sport writers of the day (no smarter then than now). The Damascas of the day was just as strong as "fluid" steel of the day. This did not change until 1930 with the advent of the Winchester Mod 21 and the Browning Superposed which were the first two shotguns of truely modern steel.
Two Parker #2 frame 12 Ga shotguns were tested with proof loads and strain gauges. One was pitted Damascas and the other "fluid" steel. They were tested at 2000 psi increments starting at 10,000 psi. Both blew their barrels at between 29,500-30,500 psi. As you would imagine, they were made to the same strength, originally.