Yesterday, the Supreme Court sent Maloney v. Rice — the challenge to New York’s nunchaku ban — back to the Second Circuit. The Second Circuit had initially rejected the challenge on the grounds that the Second Amendment was inapplicable to states. Now it will probably have to decide whether nunchaku count as “arms” for Second Amendment purposes. For my analysis of what “arms” should mean, and for citations of opinions on whether weapons other than firearms should qualify under state constitutional right-to-bear-arms provisions, see PDF pp. 19-23 of my Nonlethal Self-Defense, (Almost Entirely) Nonlethal Weapons, and the Rights To Keep and Bear Arms and Defend Life, 62 Stan. L. Rev. 199 (2009).
I should note that some bans on particular kinds of weapons might be upheld on the grounds that, even if the weapons aren’t arms, the law (1) leaves open pretty self-defense tools that are at least pretty much equally effective, and thus (2) doesn’t substantially burden (and therefore “abridge”) the right to keep and bear arms in self-defense. (See PDF pp. 12-19 and 41-45 of my Implementing the Right To Keep and Bear Arms for Self-Defense, 56 UCLA L. Rev. 1443 (2009).) But I suspect that the ban on possessing and therefore carrying nunchaku can’t be justified on these grounds, since in New York people aren’t generally free to publicly carry guns and other effective self-defense weapons (except pepper spray, but I don’t think that’s quite interchangeable with nunchaku).