First we have this test described by Jack O'Connor,

Jack O'Connor Outdoor Life 1942
A good many people resent being told that their much loved old guns were no longer safe. Just for the fun of it, Lou Smith (President of Ithaca Gun Co.) proofed (using 17,500 psi Proof Loads in 1942) a dozen or so damascus and twist beauties which were lying around the plant. Here's the dope: Most of the old timers busted loose with the first proof shell. The rest did with the second. Guns tried were cheap, medium priced and expensive: but all of them went. So if anyone wants to go ahead using modern smokeless stuff in a gun built for black powder, he can; but he can include me out.


Then we have the testing done by Sherman Bell in the Double Gun Journal which tested a Parker GH Damascus barrel that took 29,620 psi before the chamber blew.


So which one is correct? Or are both correct? Or are both wrong?