Firearms in Australia are grouped into Categories determined by the National Firearm Agreement. These categories outline different levels of firearm control. The categories are:
Category A: Rimfire rifles (not semi-automatic), shotguns (not pump-action or semi-automatic), air rifles, and paintball markers. A “Genuine Reason” must be provided for possession of a Category A firearm.
Category B: Centrefire rifles (not semi-automatic), muzzle-loading firearms made after 1 January 1901. Apart from a “Genuine Reason”, a “Genuine Need” must be demonstrated, including why a Category A firearm would not be suitable.
Category C: Semi-automatic rim fire rifles holding 10 or fewer rounds and pump-action or semi-automatic shotguns holding 5 or fewer rounds. Category C firearms are strongly restricted: only primary producers, occupational shooters, collectors and some clay target shooters can own functional Category C firearms.
Category D: Semi-automatic centre-fire rifles, pump-action or semi-automatic shotguns holding more than 5 rounds. Functional Category D firearms are restricted to government agencies and a few occupational shooters. Collectors may own deactivated Category D firearms.
Category H: Handguns including air pistols and deactivated handguns. This class is available to target shooters. To be eligible for a Category H firearm, a target shooter must serve a probationary period of six months using club handguns, and a minimum number of matches yearly to retain each category of handgun.
In some states certain antique firearms can be legally held without licences. In other states they are subject to the same requirements as modern firearms.
All single-shot muzzle loading firearms manufactured before 1 January 1901 are considered to be antique firearms. Four states require licences for antique percussion revolvers and cartridge repeating firearms, but in Queensland and Victoria a person may possess such a firearm without a licence, as long as the firearm is registered (percussion revolvers require a license in Victoria).