Privateers were a thing and popular well before, during, and after the war for independence, at that time a single warship could very well decide a battle by simply sitting near a coastal port city and threatening to shell it.Not to hijack the thread but this is an interesting question. How do we define an 'arm'? Is it limited to something one person can carry alone? A cannon?
Can my crazy neighbor and his drinking buddies obtain a howitzer and leave it parked in his front yard aimed at city hall?
Can a rich guy buy a suitcase nuke and leave it in his basement 'just in case he needs it'?
There's an argument against nukes and missiles, but if a private person could own and operate a ship of war and run around sinking pirates, I want my own personal Iowa please.
Jokes aside, it is my opinion though that honestly they should have to change the constitution or put in an amendment to clarify what exactly 'arms' means because otherwise you run into so many definitional problems (which hasn't stopped them before). The problem is, nobody in their right mind would trust the government right now to 'redefine arms'.
That's my two cents anyways.