Well, I don't subscribe to the "living document" philosophy. I have always believed that the constitution is written, plainly and simply and means exactly what it says. So in my opinion the firearms we may see in the future would fall under the protection of 2A.
My basis for that theory is that just as the 2A does not specifically say musket it also does not say firearm. It just says arms.
The battle cry: TO ARMS, TO ARMS. has been said for ages. Did you ever hear them say TO SWORDS? or TO PIKES?
