When you trim and chamfer a case you get a sharp edge that can shave a coating off. But flaring a pistol case usually solves that. You could dip the bullets in a thinned solution of Lee Liquid Alox to lube them directly. You could also sprinkle motor mica powder on the coating while it is tacky to have a dry lube coating. It resembles using powdered aspirin to give the bullets something for the pain.
