The S30 in Rev's photo is definitely the indication of a Steel barrel, 30" when it left the factory and like Doug says. a Damascus barrel will have a D, plus the length. I have owned at least one of all the marks ,S-Steel, T-Twist, K-Krupp, and D-Damascus.. I have had several high grade Meridens and the show some very high quality engraving, super wood and workmanship equal to any American SxS and for reasons unknown to the Hunter Brothersn no cracks behind the lockplates... MDC