Originally Posted by liquidorange

a disadvantage would be rust after you expose the coated metal. another one i suppose is removing too much material that you run out of hold on the screws. how many gajillons of scopes have been mounted without lapping and with 5$ rings and still doing fine.my personal preference is to use one piece scope bases when possible . there are some scope rings that dont benefit or need lapping like the buris zee signature because it has a plastic insert or warne style rings that close on a scope more like a clam shell. if your worried about ring marks just use a thin coat inside the rings with liquid electrical tape. lapping does have benefit but i dont do it anymore.