I am not a fan of the coated bullets for many reasons, one of which is the problems associated with cleaning them. Rest assured that if you shoot coated bullets, then your barrel will never be as clean as it was before. It is almost impossible to clean that junk out of your barrel. In fact, some gun custom gun manufacturers strongly advise against the use of such bullets.
BUT, since you have already used these types of bullets, try using JP Bore Past, as well as the Barnes copper cleaner/remover. It will take a great deal of time to get most of the coating out of your barrel. Just be very patient.
Zachary