The RCBS Supreme Die Set combines an RCBS Full Length 2-die set with a shell holder and Chamber Case Length Gauge. RCBS has been making some of the best reloading equipment for over 60 years. These steel, 2-Die sets are known in many reloading circles for their high-quality. Each 2-Die Set includes a full length sizer die which has an expander-decapping unit to remove the spent primer while expanding the case mouth. Vent holes prevent case damage caused by trapped air or excessive lubricant. The seater die includes a bullet seater plug and built-in roll or taper crimp as appropriate for the particular cartridge.