Here is another idea for consideration. When the barrels were assembled into a bundle for brazing together, the barrels had "flats" filed on the sides, where they came into contact with the top and bottom wedges/rib extensions. When a close fit was achieved, everything was cleaned and wired together with flux and brazing material in the joints. Then they were heated until the brazing material flows. Sometimes the bundles were heated until they "glowed". If one of the flats on a barrel was filed too thin, itself a problem, the too thin section would be more likely to "burn" in heating the bundle. After assembly, this couldn't be seen by an inspector and if it passed proof, it would be passed to the public. One proof load doesn't always show a defect, sometimes it takes repeated "shocks". Rechambering the gun is not what caused the incident.
Mike
