Used RCBS .58 caliber 500 grain Minie ball mold. This quality single cavity mold is machined to ensuring clean casts time after time from solid cast iron blocks. Cast iron blocks are precision ground square prior to machining cavities. Steel alignment pins are used to ensure perfect mating of the mold blocks even after years of use. All RCBS mold blocks feature a 3/16" thick solid steel sprue plate that is held tightly in place with tempered steel spring washers and screws. This set of used mold blocks includes a set of RCBS handles.