When the constitution was written arms meant personal firearms of the sort common to militia and soldiers. The gray area isn't h-bombs, it's machine guns that are typically operated in two man teams.
The founding fathers specifically wrote and intended for citizens to have deadly firearms of the sort carried by soldiers. If that conflicts with an orderly, safe modern society, the solution is to amend the constitution. But the constitution is written to allow citizens to have M-16s and M-4s, because that is what soldiers are issued. Arguably the M249 SAW would also qualify in the same sense, and it is full auto, thus blanket prohibitions on full auto weapons would be unconstitutional.
That the founding fathers could not anticipate the deadliness of M-16s is irrelevant and only in quite recent times have we been concerned about the framers short sightedness. Lots of men returning from WWII held onto their M-1 Garands, BAR or model 1911 (or bought it or bought a replacement). This was not controversial at all.
Once you start tortuously reinterpreting one amendment in the bill of rights you weaken them all. I'd rather keep it strict and have more amendments, difficult as they are to pass. We managed to ban alcohol and unban alcohol in the span of a couple of decades. Amendments are not impossible.
If I come off as a NRA gun nut, I am not. I don't own a single firearm, though I have training and have fired several hundred rounds at ranges. Other people with guns freak me out.