A syringe (114) is received with a housing, the syringe having a bore terminatingat a forward end in a hypodermic needle (118) and at a rearward end in a flared opening(210) in which a bung (134a) having a bore (206) surrounded by a skirt (208) is inserted.A drive element (134) has a forward end consisting of a substantially flat annularregion (200) that bears upon the skirt of the bung and surrounds a conical middleregion (202) that is received in the bore (206) of the bung. An actuator advancesthe drive element (134) so as to advance the bung and discharge the contents ofthe syringe through the needle (118). The opening (210) in the rear of the glasssyringe is flared by being provided with a radius. The combination of the radiusat the opening and the projecting conical middle region of the drive element allowsmisalignments of the two to be managed during automated assembly.