The move blocked an expansive state law, the Second Amendment Preservation Act, and let stand a ruling that it was an unconstitutional attempt to nullify federal laws.
The proposed rules are part of President Biden’s piecemeal efforts to enact a key policy goal, universal background checks, which has been repeatedly stymied by congressional Republicans.
Popular devices known as “switches” are turning ordinary pistols into fully automatic weapons, making them deadlier and a growing threat to bystanders.