This should give you an idea on the rules here in New South Wales, Australia in regards to what we can and can't have and the rules are very similar in most states.
When there was a massacre down in Tasmania back in 1996 the then Prime Minister,John Howard took it upon himself to try and score political points by trying to ban most types of guns,mainly semi automatic shotguns and rifles saying that by taking more guns out of the general public's hands would stop these types of incidents happening and went on to say that gun crime would drop dramatically but before the massacre gun related crime was already dropping.
He introduced a firearms buyback that cost the Australian taxpayer $500,000,000 and did very little but it was seen as a major step forward in political point scoring and he was anti gun as well.
In NSW and a lot of other states there was a firearms registry introduced and this was another waste of money as it was hacked into and firearm's owner's personal details were hacked plus the registry's details of who owned what was that far out of date it wasn't funny plus we have to go through a safe check every 4 years() to make sure that everything is in order something most general duties Policemen regard as a great waste of their time.
There is now a push to get rid of the registry as it's so ineffectual that it's just a waste of tax payer's money(around $74,000 a day to operate) but the anti's are under the illusion that this will promote more gun crime.
Another mistruth that the anti's are using is that most gun related crimes are from guns that have been either stolen from or sold on the black market by legal gun owners but then about 2 weeks ago it was bought to light that there was a group of Custom's people(about 20) who were allowing certain containers into the country without checking them that were full of drugs and firearms.