Let's be quite clear about this. The government passed a law allowing it to commit an armed robbery. Taking peoples' property against their will, without compensation or just cause, is theft. The Australian government is (or, at least, was) composed of thieves. The demonicrat party is also composed of thieves.
Don’t know if it’s true, but according to this article, gun owners were paid “a fair price, set by a national committee using market value as a benchmark.”
http://www.vox.com/2015/8/27/9212725/australia-buyback