Lyman 38 Spec/357 Mag Carbide 4 Die Set 7680200 LYMAN .38 Spl / 357 Mag / 357 Rem Max 4 DIE SET 7680200 Lyman Carbide 4-Die Sets feature a separate taper crimp die and two-step neck expander M die. The M die improves the accuracy of case and jacketed bullets. Like standard expander button styles, the M die doesn't stretch the case. Working in a two step process, the first step expands the inside of the case neck to just under the bullet diameter. The second step expands the case mouth to bullet diameter or slightly over so that the bullet can be started perfectly centered. Carbide dies do not require the use of case sizing lube. Die Types Included: Full Length Sizing Die (with carbide sizing ring and one-piece decapping unit) Two Step Neck Expander M-Die Bullet Seating Die Taper Crimp Die.