For practice at least I am switching to cast bullets at least in .303 to start but the intention is to use cast in another couple of rifles later on. Now I understand that for any chance of good grouping with cast bullets the jacket fouling MUST be removed from the bore. Seems the cast bullets don't like it so in preparation for this I took the No4 Sporter out (P-H Supreme) and although the bore looked clean when peering from the breech, all nice and shiney , when using a strong light directed onto the sides of the bore at the muzzle traces of jacket fouling could be seen.
First stage is to scrub the bore with a bronze brush dipped in P-H 009 Nitro Solvent to get the powder fouling out so the Forest Bore Foam can work on the jacket fouling. Despite it looking clean after a dozen strokes of the bronze brush and and second dip in the 009 then left to soak for 1/2 hour. The patch came out black when the bore was wiped through. So another two patches made the trip down the bore. Fouling was still evident so the process was repeated. Followed by the application of the Bore Foam which was left to work with the rifle standing muzzle down on a paper pad for an hour. The patch used to wipe through came out blue. So another application was called for. In all three applications of Forest were applied and there is still a hint of fouling but that's not the bad news.......................... Oh no .
On closer inspection now the jacket fouling is almost gone it has revealed fine pitting of the lands. According to the Birmingham View mark this rifle was converted in 1960 to it's present sporting configuration and although it shows little sign of hard use being in fine condition obviously this jacket fouling has lain in the bore for many years. In the past I had only cleaned with P-H 009 and have not shot this one much. Probably less than 60 rounds since I acquired it and looking from the breech the bore looked clean.
If it had not been for the intention to use cast bullets then I might not have discovered this at all and of course all the while any moisture could continue to work away under the jacket fouling. Of course it may have been shot with corrosive ammuniton in the past and not cleaned properly to neutralise the primer residue ............................... but 50 years later we will never know for sure.
The fine pitting is not enough to spoil the plans and hopefully we can over come any issues but it made me wonder how many rifles that on a casual inspection look very good in the bore actually have hidden issues under that jacket fouling?