I would contact RST

Email Address: info@RSTShells.com

Phone: 570-553-1651

and get their information on pressures and which shells to use for a damascus black powder proof gun.

I have used handloaded 1 ounce loads on wild pheasants successfully, and grouse fall to my 7/8 once 2-1/2" handloads. But, I haven't used RSTs for a few years...

Some of the other members of this board may have used RST shells in damascus guns and may know which to choose...