When using the Lewis Lead Remover, rotate the Rod while pulling it through - especially at the end. Let it work the end of the Cylinder Charge Hole a few rotations before pulling it out completely. IMHO the LLR works the best out of any method I've tried.

I also use the Brownell's Chamber Brushes as dfariswheel has mentioned above - but not in a drill as some do. Works when leading is light to moderate, but the LLR works for heavy leading.