The legal standard for granting the government permission to remove the right to keep and bear arms across the board is for weapons that are dangerous AND unusual.

Few own nun-chucks, hence it’s not actually illegal to ban them.

Weapons commonly possessed for lawful purposes may NOT be banned.

But of course everyone pretends they don’t know this standard when passing laws and hence there are always lots of court cases taking their sweet old time to come to the forgone conclusions.