doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com NDT Pattern Welded Barrels Update

"I don't think anyone in the country has the expertise to interpret Pattern Welded barrel radiography at this point. "

You have finally determined the crux of the matter.
Which is one of the problems I tried to convey to you.
I don't know whether you have used the services of a Level III NDE Expert.
A Level I on can only perform the examination, Level II can perform and evaluate tthe examination BUT ONLY to a procedure and criteria developed by a Level III Expert.
For a LEVEL III to develop a procedure and criteria you have two options or combination of options.
First is to the prepare barrels with known defects, radiograph and compare.
The second is to radiograph barrels with suspected defects and then section to compare.
From a set of objective examinations/radiographs, try to develop a procedure and criteria for evaluation.
If you offer this service for monetary gain, you will have to have Insurance from an ASME Insurance Company such as Hartford Steam Boiler.
In this country, you cannot operate pressure retaining devices nor offer service for those devices unless you have insurance from a company such as Hartford.
Now shotgun barrels are not exactly pressure retaining but they come close in my opinion.
Now throw in the myriad of fabrication techniques that were used in the past with steel/iron that may have who knows what mechanical properties heat treated in who knows what way and you have some sense of the problem.
So the best you would be able to do is to determine a defect exists, the extent and type of the defect, inclusion, linear crack or what have you but you will not be able to determine if the barrel is safe to shoot or not,
Even with a proof test(which was devloped to eliminate barrels with internal problems because NDE did not exist at the time), you cannot fortell the future for susequent firing, you assume some risk.
Have you used the services of a Level III certified by the ASME?
Have you seen or have a copy of the Certification?(Trust but Verify)
I understand your attmept to develop some way of assuring that these barrels are safe to shoot but I still don't think that is possible to where you can provide Certification within known standards.
Certainly what you have done is very interesting.-Dick
BTW in my career in Nucelar Power I developed a Quaity Control Department complete with all Levels of NDE capability. I had to solve many problems involving NDE techniques that did not exist. In some cases due to configuration, it may not be possible to develop a procedure and criteria.