Made from polished and Heat-Treated steel, the RCBS carbide 3-Die set has a sizer die with decapping unit, expander die for expanding and Belling the case mouth and a seater die for seating and crimping the bullet (straight wall cases will roll crimp, unless the description indicates it has a taper crimp). no sizing Lube is needed with these carbide dies. Type: 3 die set fits: 41 Remington Magnum note: uses shellholder #30 (sold separately).