A couple years ago, one of our members who happened to be a metallurgist and had access to a met lab, embarked on a project to test the mechanical properties of steels/damascus of late 1800s/early 1900s gun barrels. I don't know where he is in this project, but I believe he may have had a sample of a krupp steel barrel...but of what vintage and alloy, I don't know.
Even if he had data on a Krupp sample, it would be unwise to directly correlate the data to your gun, for many reasons. Best to stick with loads with pressures for which the gun was designed. That was your question of course and you are headed int he right direction. But, without the gun make and vintage, this crowd won't be able to provide any useful information. As you probably know, Krupp steel barrels are still being used today on some maker's modern guns (Galazan for one).
