A nozzle assembly for a needle-free injection device. The nozzle assembly includes a nozzle body including an injectate chamber and one or more outlet orifices and a plunger configured to move through the injectate chamber toward the one or more outlet orifices. In some embodiments, the plunger includes a first portion and a second portion removably joined by a frangible region. In some embodiments, the plunger includes extensions configured to couple the plunger to a drive assembly of a needle-free injection device.