If you have somehow gotten dips and high spots in you barrel you are approaching draw filling incorrectly. First off just to be clear, draw filling is done with a mill file placed directly cross ways at 90 degrees to the barrel. then filing inline with the barrel while applying moderate pressure on strokes of say 6-8". Carding (cleaning) you file as you go. If you have managed dips and high spots you will have to level those by working the high spots down.