This is a clear violation of the Second Amendment. As the Supreme Court noted in Heller, the dictionary definition of “arms” at the time of ratification was “weapons for offence, and armour for defence.”
If further proof is needed that the Second Amendment protects the right to keep and bear armour, I seem to recall, in the late 18th and early 19th centuries, that several cities hosted militia units armed and equipped in the manner of Napoleonic heavy cavalry (hussars, cuirassiers, and the like). These units were manned by wealthy citizens who almost certainly provided their own armor. Might be a fun research project to confirm this.
Given that the 2nd Amendment applies, I don’t see how this law meets any level of scrutiny. What legitimate government interest is served here?
“This is a clear violation of the Second Amendment.”