just regulate magazine sizes that are open to the public. 10 round mag is big enough, hell, it might be too big. but if your going to buy 30, 50, 100 round mags for your gun, thats just idiotic.if you get those mags, your either gonna kill people, or your a terrible shot when target shooting.
the second amendment to the United States Bill of Rights exists (right to bear arms), but if it were entirely up to the government, that would be the first right they would take away, because in their eyes, taking away guns means the crime rate will go down, when in reality, criminals would not follow a law banning guns.. because, their criminals. and if anything,crime rate will skyrocket.
i don't know about Australia's ban on certain guns, or if it has anything to do with the lack of mass murders, but, i can almost guarantee that in general, crime-rates have increased.
logically, if every family in both America and Australia owned at least one gun, both of their crime rates would go down.
Australia has more guns now than at any point in history, certain types of weapons have been made harder to get but guns have never been common in Australia except in rural areas where people have a decent reason to own guns (defense of property by murdering someone is not considered an acceptable reason in most civilised nations).
Crime has risen in Australia but homicide has dropped, most of the crime in Australia is directly related to alcohol and drug addiction, something guns will not solve in anyway. Domestic violence is a big problem in Australia, adding guns to the mix is just going to turn wife-bashers into wife-shooters.
There is absolutely nothing logical about your last statement, criminals in Australia rarely have guns because its incredibly hard to smuggle guns onto the island and before the '96 gun laws were introduced we already had a comprehensive gun registration and licensing system.