An incredibly illuminating time with Adam at METL, who has an interest in damascus/wootz blades and has visited Al Pendray's shop in Gainesville.
Boy was I/most of us confused
1. This is rivelling from plastic deformation during the rupture - NOT the crolle pattern. I think Will & Craig called this one
2. Adam, on initial examination, did NOT identify low cycle fatigue but suspects an area of embrittlement at the forward, lower point of the blow out. He agrees the deformation superiorly looks like there was a bulge.
3. Unfortunately, composition testing by EPX, SEM, or OES will require a piece of a Damascus demonstration rod at least 1" X 1" and with the layers of steel and iron at least 1/16". The dense matrix of iron and steel will not allow analysis of each component
separately.
SO if someone would please whack off the end of their demonstration rod, we could do the testing, then try to match each with the modern equivalent
4. Photomicrographs of the barrel wall
should give us a definitive diagnosis, AND identify interlaminar rust, voids, inclusions, micro-fractures, defects. Adam does NOT think the fracture lines follow weld lines.
5. Adam does not believe MPI/Magnaflux testing would be the best procedure to identify defects in the barrel walls by NDT.
Gloria a Dios there is
another testing lab in Phoenix that specializes in radiographic (x-ray) testing of metal and I will set up a meeting with their engineer.
I'll have two barrels for radiography; one of which could then be sectioned to identify any defects found on the x-ray testing and possibly blown up to see if the blow out occurs at the defect.
Adam shares my excitement about doing something no one has done before, and I am hopeful that the x-ray testing (of course combined with wall thickness, chamber, and bore evaluation) may be a way, and at less cost, to establish a GREATER (but not definitive) level of confidence in the safety of Damascus barrels.
Again,
many thanks to all who have contributed opinions and suggestions!! 
