Came up with this:
"Damascus or twist-steel barrels are made by layering alternate strips of steel and iron then welding them together. The strips are then twisted until they resembled a screw, three of these wound strips are then welded together, wound around a steel mandrel, then welded and hammered into a barrel tube. Laminated steel barrels are a bit different. They start with a ball of steel and iron that is then hammered into long strips and twisted, then, like their Damascus cousin, wound around a mandrel, welded and hammered into a barrel tube."
From The Shotgun Encyclopedia by John Taylor
It would be a fascinating trip to explore the Belgian Patent office (if I spoke French.) It's likely most of the Belgian damascus patterns were patented, and likely the patents were ignored as all the members of Syndicat des Fabricants de Canons de Fusil de la Vesdre made 'Bernard', 'Boston', etc.
Desire Mineur, of Prayon, Liege, claimed exclusive rights to "Chain-pattern" damascus in 1904, despite the fact that the pattern had been used for at least 20 yrs.
