Well I at least temporarily stopped trying to get the lead out of my Caimans CZ barrel today when more slugs arrived. The lead is all in the first few inches of the barrel none near the crown. It is at worst thin now, seemed much thicker initially. I got a couple "Chore boy" pure copper scrubbers. I wrapped this over the first brass brush I used to make it tight in the bore. I kept the bore wet with Kroil but I am not sure it did much. I hoped it would loosen the lead but it seems tightly adhered.
I put a couple magazines of slugs lubed with WD40 through the gun late this afternoon. Velocity was about 920fps, about the same as before. 5 of the last 6 shots were 280mps and the other one was 281. It varied more on the first 14. Accuracy does not seem to be improved, may be worse. But I probably over lubed the slugs and haven't tried any tuning adjustments. The pictures are a couple areas with the most remaining lead taken with the mirror on the bore scope.
View attachment 545536 View attachment 545537