[Big Friend Ten (BFT)]

Harold,

Safe peak pressure in Damascus should be based on barrel wall thickness from the chamber to about 15". After that the pressure is so low that an old steel can would contain it. A barrel that thin would however dent or bend far too easily!

I have heavy Damascus barrels that will handle modern shells to the SAAMI mean working pressure. I also have a 16 gauge Lefever and a few #1 Frame Parkers with seeming untouched barrels that I would NOT shoot modern ammo. Oh, I think that would be fine but why take the chance? Certainly the recoil from modern loads (not necessarily high pressure loads) would not do any good for the stocks!

Loads at 6000 PSI are safe for almost gun with Damascus or twist barrels in the condition or close to as what they were when they left the factory. I don't worry much about 8000 psi but then I don't shoot guns with barrels with pits the depth of the Grand Canyon! If fact I did buy a DHE Damascus that measured about .016" where my forward hand would be. Although with 6000 peak psi loads they would have been safe I retired those barrels from service and rebarreled the gun. Why, because I might screw up someday and shoot a high pressure load in it. Or, maybe the net caretaker would. I am a big fan of fingers!

So, all the above stated, 6000 psi should be safe but have your barrels measured if you have doubts. My Hosford Barrel Wall Thickness Gage may have save my fingers in reference to the above described barrels. That may have been the best $600 I ever spent!

I'd have Damascus or twist barrels measured before I subjected them to 9000 psi peak. Even a heavy barreled gun may have been honed too thin. It is hard to maintain the concentric relationship of bore to outer diameter when honing without special tools. Even original Parker bores may not be as concentric as what appears to the eye!

Shoot well and shoot safe!
Mark