Glad this came up and here we go:
"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

Last edited by revdocdrew; 06/16/07 11:56 PM.
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