I use a exacto blade in a wood dowel taped to fit the I.D. of the hull with a bit of clearance. A wood screw is in the bottom to set the length. For the best roll crimps it is necessary for the hulls to be the same length. If the wad column and shot do not come to the same height I add a few pellets to bring them all level. About 3/6'th inch of hull over the overshot card works well. Setting the stop on the drill press insures that you do not mash the crimp. I do not skive, lube or heat the hull or crimper. I use a Precision crimper and a BPI hull vice for this task. Do not make this too difficult because it really is not. Just uniformity along the way. Uneven lengths make the crimps look frazzled or twisted. The set stop makes them all look the same.
