This finely ground carbide cutting pilot designed for use with the K&M neck turning body has four cutting flutes used to remove the "dough-nut" that can form at the inside neck wall and shoulder junction. If you are noticing the formation of a doughnut, this tool will remove the excess material without affecting the inside neck diameter. This allows for uniform bullet seating and eliminates powder gas restriction. There is also less friction between brass and carbide; this translates into less heat buildup and galling. FeaturesMade Specifically for the K&M Neck Turning ToolCarbide reduces friction caused while turning brass Cutting teeth on end will remove the dreaded case "doughnut"