A bayonet lug

New Zealand's gun laws are notably more liberal than other countries in the Pacific and focus mainly on vetting firearm owners, rather than registering firearms or banning certain types of firearms.[4] Firearms legislation is provided for in the Arms Act and its associated regulations, though stricter unofficial police and government policies also apply[citation needed].
Categories of firearms

Firearms in New Zealand fall into one of four categories:

    Pistols are firearms shorter than 762 mm (30 in).
    Restricted Weapons include machine guns, selective-fire assault rifles, grenades and rocket launchers. This category also includes some non-firearm weapons such as pepper spray. Cabinet can declare things to be restricted weapons by regulation.
    Military-Style Semi-Automatics (MSSAs) include semi-automatic rifles and shotguns that have one or more of the following components:
        A folding or telescopic butt
        A bayonet lug
        A military pattern free-standing pistol grip
        A flash suppressor
        A magazine that holds (or looks like it could hold) more than 15 rounds of .22 rimfire ammunition or 7 rounds of a centrefire calibre.
    A Category firearms are those that do not fall into any other category, and are the vast majority of legally-owned firearms in New Zealand.

Registration is not required under the law but the police carry out a regime similar to registration for all but "A Category" firearms. Firearms in any other category require a "permit to procure" before they are transferred.