This kit converts the 5mm Magnum rimfire to 5mm Magnum centerfire making the cartridge reloadable. The new bolt head was installed on a rimfire bolt body but never fired. It comes complete with extractor which functions perfectly. Included is: RCBS 5mm Remington Mag centerfire dyes Cost $110.00, 65 unfired, unprimed cases, 166 Schroeder 40 grain bullets, and complete instructions. This kit is perfect, like new!