Well, it is an attack to restrict firearms ownership. Remember the original purpose of the 2ed was to arm the citizenry against tyrrany. So if government can restrict your access or avaiability of firearms (especially those said government actively uses in its military) they are restricting your ability to arm yourselves against them.

It doesn't hurt that the framers didn't conceptualize nuclear weapons or ICBMs, though. Back in 1800, it was perfectly reasonable to expect if the US military could have a mortar, a citizen could. Though I'm more of the opinion if you wouldn't trust your neighbor with some destructive tool than you shouldn't trust the US military with it.