[ta98789878]

It's frustrating to keep seeing people use the phrase "buyback" when they mean "confiscation". In the US, at any rate, a "buyback" is voluntary. For linguistic comparison, the taking of land by eminent domain includes compensation, but one certainly would not say the government "bought" the land.

[dalbasal]

In Australia it was voluntary.

[Zak]

"You may sell the thing that's about to become illegal for you to possess to the government for a price set by the government" stretches the definition of voluntary.

[ta98789878]

Classes of firearms were made illegal. Do you mean the newly illegal classes were grandfathered and those owned before the ban could be legally kept by their owners?