WD-40 does not last forever. It is a light machine oil. Not a lubricant and left out in the open will evaporate in about 15 minutes. WD-40 will evaporate in closed spaces much slower. A wool mop will attract moisture over prolong periods of time. And moisture in chambers will cause problems over time.
In my Fox the paper hulls had deteriorated and the wax coating was long gone. The brass was corroded and stuck in the chambers. I drove them out with a cleaning rod. The paper attracted moisture and the long term result was badly pitted chambers. The lady I bought it from said it had been stored like I found it for over 30 years. I thought it was loaded with live shells but they were two empty hulls. I suspect he late husband used them as snap caps and forgot about them or never checked them and then passed away.
They were so bad I would not shoot them. I could have had Briley chamber sleeve them back to 16 but I already had a couple 30” Sterlingworth 16’s, but no 20 gauge 30” guns. So I went down one gauge and fitted a new 20 gauge extractor. In part I figured the extra thickness of metal, going from 16 to 20 would help make the chambers safer. Most likely it did nothing but extra metal never hurts. My son, in northern Ohio has the gun now and likes it for early Dove if his wife claims the Ruger 28 gauge. It patterns great and we left the full and full chokes as original from the factory.
If I come across another 20 gauge set of barrels with the same issue I am going to have it chamber sleeved down to 28. About the only way I’ll afford a 28 Fox. I’ve got a couple 26” orphan barrels but a 28” or 30” 20 gauge barrels are going to be a tougher find. At least it has for the last 20 years.
So if you use WD-40 make sure you refresh it from time to time or use a better gun oil. Just use it sparingly.
