Hello,

I need to remove some nasty deposits inside the valve of a 1400 Winchester shotgun.
It is a black substance, probably some kind of carbon formed with the shotshell gases.
I try WD-40 and destilled petroleoum, but that dirt refuses to remove, even with an overnight treatment.
I use a bronze brush and it makes scratches in the deposits, but that stuff is really difficult to remove.
Any advise about a good solvent to remove that mess?

Thank you, as always, for sharing your knowldege.

Best,

Jose M. Fernandez