I don't own or shoot Damascus. However, I believe it is "safe" to do so with "modern" loads, assuming either a) a reload at appropriately low pressure; or b) factory loads matching the proof level of the gun in question.
I don't even use American factory ammo (that is, from Win/Rem/Fed--with one exception) in my steel-barreled, in proof, 2 1/2" Brit 12's from the 1930's. The exception would be the low pressure "vintage" loads Federal made up for Midway, somewhere in the 6,000 psi range if I recall. I either shoot shells like RST's or Kent Gamebores, or else I reload to appropriate low pressures. I'd feel safe doing the same thing with a Damascus gun, if inspected and given a "pass" by a knowledgeable doublegun smith.
Last edited by L. Brown; 12/07/08 05:05 PM.