[SteveLAnderson]

You may not be sure, but the researchers that study this subject are sure - http://andrewleigh.org/pdf/GunBuyback_Panel.pdf

And for the US - http://www.slate.com/articles/news_and_politics/crime/2013/1...

[refurb]

It's not just me, it's other researchers as well.[1]

[1]https://en.wikipedia.org/wiki/Gun_laws_in_Australia#Measurin...

"The results of these tests suggest that the NFA did not have any large effects on reducing firearm homicide or suicide rates."[61]"

"The implemented restrictions may not be responsible for the observed reductions in firearms suicide. Data suggest that a change in social and cultural attitudes could have contributed to the shift in method preference.[60]"

I wouldn't assume that it's settled.

[SteveLAnderson]

The paper I linked to discussed both of those papers and corrects errors made in them.

[refurb]

Care to point it out?

The table I'm looking at says firearm suicides dropped by 50% prior to the gun buyback.

I'd argue the decrease in overall suicides is a general trend happened to coincide with the gun buyback.