http://www.nytimes.com/2013/01/17/op...too.html?_r=3&

A study by McPhedran and Baker compared the incidence of mass shootings in Australian and New Zealand. Data were standardised to a rate per 100,000 people, to control for differences in population size between the countries and mass shootings before and after 1996/1997 were compared between countries. That study found that in the period 1980–1996, both countries experienced mass shootings. The rate did not differ significantly between countries. However since 1996/1997, neither country has experienced a mass shooting event despite the continued availability of semi-automatic longarms in New Zealand. The authors conclude that “the hypothesis that Australia’s prohibition of certain types of firearms explains the absence of mass shootings in that country since 1996 does not appear to be supported… if civilian access to certain types of firearms explained the occurrence of mass shootings in Australia (and conversely, if prohibiting such firearms explains the absence of mass shootings), then New Zealand (a country that still allows the ownership of such firearms) would have continued to experience mass shooting events.”


You can find the full report here: http://www.ncbi.nlm.nih.gov/pubmed/22551044


And nor has it made much of a difference to the overall Australian gun murder rate :