The two designs differed markedly in external appearance (amongst other things, the New Zealand Charlton had a forward pistol grip and bipod, whilst the Australian lacked this, making it lighter and cleaner in appearance), but shared the same operating mechanism.
Two versions of the design stood out due to their distinct appearances (the New Zealand Charlton featured a prominent forward grip and bipod, whereas the Australian model was simpler in design, resulting in a sleeker look), yet they both utilized the same functional mechanism.