An exemplary embodiment of the invention is a nozzle, for use in an injection device, that projects material at an ultra-high velocity. The nozzle includes an integrally formed body having an interior passageway that has a longitudinal axis. The input of the nozzle is configured to interface with a cartridge, and the output is configured to be placed proximate to a target. The passageway includes a taper, and its path length, from an initial diameter to a position along the passageway where the passageway first reaches a smallest diameter, is at least 0.5 mm. The taper of the passageway defines a shape, in a plane that includes the longitudinal axis, that is a continuous and monotonically decreasing function of distance along the longitudinal axis in a direction of flow through the nozzle.
