Abstract: A method and mold for making an ampule for a needleless or jet injector device. The tip of a core pin is guided into a clearance hole sufficiently large to prevent the tip from hitting the mold cavity. Plastic is injected into the mold and flows into the space between the core pin tip and the clearance hole forming a vestigial nozzle pilot cylinder around and over the ampule nozzle. The ampule is removed from the mold and the vestigial nozzle pilot cylinder is removed to form a finished ampule. A core pin tip is made of drawn wire or is separately replaceable on the core pin. A nozzle of an ampule is cast in place. An ampule is molded with an enlarged nozzle and a separate orifice is installed in the ampule to provide the desired nozzle opening.