I disagree: I think the reference to "arms" was originally understood as applying primarily to small arms, not artillery. I think, in the first few decades of the 2nd Amendment being in force, federal restrictions on purely private ownership of artillery – and especially large artillery – would likely have been upheld, while federal restrictions on purely private ownership of small arms would almost surely have been struck down. While people at the time could not have foreseen nuclear weapons, they are more like large artillery than small arms, so I think federal restrictions on purely private ownership of them would likely have been upheld even given the original meaning of the 2nd Amendment. (By "purely private", I mean to exclude military units organised by state or local governments.)