Presumably, hopefully, FN would have used a non-corrosive rosin flux to solder ribs so it will probably never be more than an annoyance. Maybe take some of the weeping residue and put it on bare steel in a damp place and see if it rusts more or less than a part of the steel that is not coated with the residue. If you can prove to yourself that it is not something that is eating into your barrels between the ribs, then you can weigh the cost of a relaying job against a little extra cleaning.

Voting for anti-gun Democrats is dumber than giving treats to a dog that shits on a Persian Rug