Tom: there is more information here, including the CIP recommendations for Fluid Steel barrels.
https://docs.google.com/a/damascuskn...vwLYc-kGA/edit
We now know that the tensile strength of Pattern Welded barrels is about 1/2 of even vintage fluid steel, reinforcing the importance of using loads that match ballistically those for which the gun was designed. Until about 1920 that would be 3 - 3 1/4 Dram Eq. with 1 1/4 oz. shot with a pressure of at least 10,000 psi
https://docs.google.com/a/damascuskn...EK8OtPYVA/edit
https://docs.google.com/a/damascuskn...hIiY62Hx4/edit