A system and method for hydraulic blow molding a plastic preform into a container. The system includes a nozzle having a nozzle body with a main bore extending therethrough and an outlet for ejecting molding medium into a preform positioned within a mold. A minimum internal diameter is defined within the body of the preform, which is bound on opposing ends between an open end and a closed end. To form the container, a liquid stream is injected into the preform. The liquid stream is defined by the outlet so as to have an external diameter that is less than the minimum inner diameter of the preform, allowing the stream to impinge upon the close end of the preform without impinging upon a transition of the preform, where the minimum inner diameter of the preform is reduced from the diameter of the finish.