This is a very interesting topic. I used to use a dry lube inside the neck of the case just prior to bullet seating. About 4 years ago, I started cleaning the inside of each neck, by chucking a RCBS Neck Cleaning Brush ( White Nylon ) or a bore cleaning brush ( 30 cal. for example ) , into my drill press, and running the 270 Win cases, or .308 Cases up on to the spinning brush, making the inside of the necks very clean. This is done after all tumbling media has been removed from each case. Then Prime the case . I have not used Dry Lube since, but perhaps I should use it again !!??? Thanks Boys!!