Cherful,
Sorry to disillusion you but rapid fire firearms are readily available to licence holders.
Guns that have a sustainable rate of fire exceeding that of the banned pump-action and semi-automatic shotguns are. Category A, the least restricted category.
But, be of good cheer, the single shot muzzleloading Muskets, as used by the First Fleet are in Cat B which is more restrictive. ( in highly trained hands they can be fired three times a minute, by the less skilled one or two shots)..
The ‘deadly’ Zimmerstutzen (used for target shooting in Bavarian pubs, like darts but not as dangerous) is Cat A if breech loading but Cat B if m/l.

Perhaps the author could explain why theUS, with the highest gun ownership by civilians in the whole World has a low murder rate?

in highly trained hands they can be fired three times a minute
is Mise,
Under the proviso that they actually go off ! In those early days of invasion & subsequent conflict, 50 spears were more effective than ten guns. The only life preserving factor on the side of uninvited explorers & settlers was the 'Bang" rather than the hit & miss effect of a ball of lead which frightened off native folk for a while.