"In a un neglected Damascus gun the barrels are as strong as steel tubes or stronger."

I was hoping that was true, but it is not.

Soon to be published tensile strength testing showed both Twist and Crolle Damascus to average about 54,000 psi
Hunter Arms Armor Steel was 101,000 psi.
Published tensile strength for 4140 chrome-moly - 90,000-100,000.

HOWEVER, from Sporting Guns and Gunpowders, 1897 in a discussion of the 1891 Birmingham Proof House Report - “…the strength of the Damascus was so much in excess of all ordinary requirements that no fear need be felt of their giving way…”