....Based on where it was observed in the braze, we need to refer to it as ferrous braze contamination. We don't know exactly what it is. This could have occurred during the brazing process (likely)....
One of the pictures that I thought was interesting on the other thread showed the 'ferrous braze contamination' appearing to be completely encircled by braze. It had the look to me of what flux can do, clean oxides off the steel and allow the braze to flow. In other words, it still could be a successful and adequate braze if(?) the braze still flowed and bonded to the rib and barrel.
Some of the past pictures seemed to show braze that was still bonded to the rib, but very little to none on the barrel. I think the worrisome oxides are not the small islands that're completely encircled by braze, but the seeming unbroken sheet of oxide, possibly rust, that that looked to run along the barrel and may have penetrated the barrel in the form of pitting at what I think was referred to as the intiation point.
Back to this gun, since there's an answer to come, I'm going to guess there's another picture coming of something in the barrel. Maybe, a wad or part of a separated hull based on how far downstream the burst seems to be.
