I was told by someone who toured the factories that there was no sign of any inspectors or of a quality control in the CVA factory they visited. When ask about it they were told each piece worker inspected what they did. Any body that has worked in quality control knows what to think about that.
Any good machine shop should have a Rockwell or Brinell
BHN=2F pi D [D={D squared -d squared}
BHN = Brinell Hardness Number (N/mm2)
F = applied force (Newton or N)
D = diameter of indenter (mm)
d = diameter of indentation (mm)
There are charts for different alloys such as stainless.
Also should magnaflux and use sonar to check for laminations and such other defects.
Back in the 80's I believe the was a major problem with defective steel in CVA barrels if I remember correctly the co. changed hands after that.
I was on the firing line shooting competition when one of their barrels split I have never considered buying one since.