Abstract: The bore communicating primer pocket and the interior of the base of a cartridge case is internally threaded and a threaded shaft end is threaded through the bore to a position with the terminal end of the shaft spaced inwardly of the open end of the casing. A bullet is telescoped rearwardly into the open end of the casing an excessive amount into seated engagement with the shaft end and the entire combination comprising the shaft, casing and bullet is forwardly telescoped through the receiver of a rifle subsequent to the removal of the rifle bolt and to a position with the casing fully seated within the receiver of the rifle barrel. Thereafter, the shaft is threaded forwardly relative to the casing in order to gradually displace the bullet from the open end of the casing until such time as the maximum girth area of the bullet engages the rifling in the rear end of the rifle bore.