Damascus exterior liner
http://www.google.com/patents?id=rRlVAAAAEBAJ&printsec=abstract&zoom=4&dq=1181704#PPA1,M1



A modern rendition by Bowen Classic Arms
http://www.bowenclassicarms.com/workshop.html#DamascusBarrelSAArmy
"This particular gun started life as United States Firearms Single-Action Army model in .45 Colt. The composite damascus barrel sports an overlay of English gun tube material..."

Last edited by Drew Hause; 01/01/14 12:41 PM. Reason: Patent link added