Resently I tried some slugs out of my taipan veteran in .177. Not that I expected good results from it, but wanted to try anyway. After that I cleaned the barrel with patch worm. When I went back to pellets, I had some really bad fliers, and the grouping was not as good as before. Tried leading up the barrel, but it did not help. Since I had not changed anything on the gun, I suspected the slugs may have left some ressidue which I was not able to remove. I ended up removing the barrel from the gun and used a bronse brush all the way down the barrel. Then cleaned again with patchworm. After reinstalling the barrel, the gun was back to normal. To me that confirm my suspicon that not all can be removed with patchworm only. Had I not removed the barrel, I would probably not been able to clean it properly with a brush without ruin the O-ring. Apart from that, my taipan is probably one of my guns which require less cleaning, and I have never experianced lead fouling in before, when shooting pellets.