No, No, No. You do not want to use the Tubb Final Finish or any other fire lapping compounds in your bore, at this stage. You have been shooting that rifle for a while and the bore is broke in. Any lapping at this stage will only shorten your remaining barrel life or completely finish it off, one or the other.

The bore solvent you are using is OK for powder residue, but to get to the really stubborn copper out, you will need something like Sweets 7.62, Barnes CR10, or Montana X-Treme. If it needs further cleaning or copper removal, try a little J&B Bore Cleaning Compound.Then clean the again with one of the copper removingsolvents.