many thanks for your replies, Jim and dogon, I am positive that is the problem - flux bleeding out.
Question is now what to do about it? The rib is solid and doesn't move. Do I live with it, or get it fixed?? Wouild the whole rib need stripping off to fix it??
I would send it back to Browning, but after owning 8 new Superposed's, I have extensive experience of Brownings warranty repairs and their Belgium Gunsmiths, guns disappear into a black hole for 3 to 4 months and frequently come back damaged, screws stripped and in a worse state than when they went back to Belgium for warranty repair.
If a repair is necessary, I would far rather pay for a repair than let those butchers get their hands on it!
