By the very nature of the manufacturing process, pattern welded barrels can not be NDE tested with definitive results by any NDE process.
To attempt a Metallurgical examination is. waste of time in my opinion and for what end? The first thing that comes to mind with a re-load is of course an error in reloading. But we are talking about a 100+ year old barrel of to me of a dubious manufacturing process.
Put all these factors together and it's a recipe for disaster.
As to credentials, my degrees may be in Nuclear Engineering but I spent my Graduate years studying Metallurgy. I have investigated as Team Leader a number of Metallurgical Failures in the Nuclear Industry.
-Dick