Eye I know that you and I have already discussed this issue fairly thoroughly elsewhere but my brain has shifted in a direction that it had not before...
First off, whether the 2nd amendment is specifically talking about personal arms or not, I agree is pretty debatable, and I don't really want to get into whether or not it is.
I'm just curious, if you were to ponder on the following idea, what you'd conclude...
If the right to bear arms was derived from a duty - we must consider what that duty was... Was it a duty to keep a rifle or was it a duty to be personally prepared to defend your established society. I'd have to say it was a duty to keep a rifle because you have an underlying duty to be prepared to defend yourself and your community. The keeping and bearing of a rifle, at the time, was the most reasonable and sure way to fulfil your actual duty.
And so, if the 2A is akin, and based on that duty, then you could say that you have the right to "bear arms" specifically for (though not necessarily limited to the purpose of) the purpose of defending your self and community. If the right is based upon the duty, then wouldn't the specific ownerships adjust as what's needed to fulfil your duty changes with time? When cartridges were developed you might say that your duty and therefore your right shifted from keeping and bearing a muzzle-loader to a more modern rifle - this I'm sure we'd agree on. If it's so because now the keeping and bearing of a more modern rifle is the most effective and reasonable way to fulfil your duty, then wouldn't the same apply if the most reasonable and effective way to fulfil your duty evolved into the ownership and possession of something other than a rifle or other personal firearm?
I guess what I'm saying is, if the entire right hinges on the duty, then wouldn't the specific tools that we're entitled to own and bear shift as technology advances as to allow us to remain reasonable able to fulfil the duty, even if it means jumping classes to another type of weapon system?
Just popped into my head. Haven't given it that much thought.