There is a way plenty of fouling in my barrels, when i use BH209. However, this fouling doesn't impede loading like the fouling of 777. It doesn't seem to get worse and worse and worse with every shot. From time to time it does cause some rusting in the barrel, but not every time. I have fired near 75 shots without cleaning, and accuracy and ease of loading doesn't seem to change. Breech plugs do get more and more plugged up with each shot until the flash channel is about 1/16", and then it stays about the same. There is a way plenty of fouling in my barrels, when i use BH209.