Abstract: The invention includes retrofitting a plasticating machine for the working and forcing of plastic material into a moldor die, the machine including an elongated housing having a first or proximal end and a second or distal end, and elongated screw shaft with a screw flight therearound. The screw shaft is rotatably supported in the elongated housing, for the working of plastic between the screw shaft and the elongated housing with at least one delivery conduit generally longitudinally arranged through the screw shaft, from a location proximal to the distal tip end of the screw. To accomplish such delivery, the screw shaft is replaced with a corresponding screw shaft with a bore extending through the distal tip end thereof, or the existing screw shaft is machined to have such a bore extend therethrough, from location proximal to the distal end out through the distal tip end. The bore in one embodiment may extend completely through the screw shaft, from its proximalmost end to its distalmost tip end.