Well, having picked up the barrel group a bit earlier today to actually fly-speck it, I can tell you the following:
That the owner and I should have taken a photo of the bottom barrels under-surface (near forend lug) as the bulge there is a dramatic 1.35 in width. (I dont have a digital camera or i-phone here at the moment or Id provide you all with one, but it looks like the python that swallowed the pig.) The center of that bulge (at its widest 1.35) is a measured 5- 1/4 forward of the breech..and I apologize for not having these measurements closer to correct in my first post..being without tape or tools yesterday.
That the more concentric ring bulge in the upper barrel is .935 at its widest, that occurring right at 5.0 inches forward of the breech in spite of the photos seeming to suggest otherwise. My first glance yesterday left the impression that they were spread further apart. So, in reality the two bulge centers are almost atop one another. Also, the barrel's top rib popped loose from its stanchion just downstream of the upper bulge, and you can no doubt see that the connecting side ribs have been pushed around like spaghetti.
That the first photo (with the injured hand) shows a strap of barrel wall blown upward into the open recess between the two tubes. Though I cannot finagle a micrometer onto it for a more accurate wall thickness number, I can - under magnification get a pair of needle-tipped dividers onto it for a pretty good measurement. Taken as such, thickness of the barrel wall at 5.0 forward of breech is .095 (+/- .005) and only .070 thick (+/- .005) at 6.0 forward of breech. Owner is the original purchaser of the gun and had no aftermarket work done such as forcing cone lengthening, etc.
I promise Ill leave it at that, but thought you should have the better data to surmise from. We know not to expect anything too conclusive as to actual cause without the fired hulls having been recovered.
Again, much appreciation from this end for those who weighed in with thoughts and well wishes
Rob
