[chipsa]

The government has totally said “destroy the thing that we said was legal to manufacture, purchase, and own when it was manufactured.” That was the entire point of the bump stock ban, which attempted to reclassify an item that they had previously said was not a machine gun into a machinegun, and therefore illegal to own (and was always illegal to own, so they weren’t going to compensate people for them either).

More strictly, machine guns aren’t banned by the federal government, but rather you have to have paid a tax to own it, and they’ve banned paying the tax for gun made after X date. If they decide to ban the ownership, grandfathering is not guaranteed.