Lyman 3-Die SetsBy adding both a premium Carbide Expander Assembly and a Neck Sizing Die, Lyman has created two die sets in one. Neck sizing eliminates overworking the brass, extending case life. Lyman Carbide 3 Die Sets include: Deluxe Carbide Expander Assembly, with a free floating carbide sizing button, which smooths neck expansion by moving the button up the decapping rod to better use the press' leverage. It eliminates the need for inside neck lube. Neck Sizing