People owned warships, cannons, etc privately at that time it was written. If people shouldn't have arms such as nukes or f-15 and 'scaled up weapons' the 2A should be amended to exclude some arms.
>>...2A...
> But small arms in the context of modern government technological authoritarianism amounts to little more than a security blanket ...
The point is that focusing on weapons is futile when society is no longer ordered by overt force but rather economic/pragmatic attractors. In the western world the battle based on physical force has essentially been fought and won permanently - the result is democracy which is a similar dynamic without most of the violence. If a critical mass of people come together and want to change things, then that happens. The system has responded by dividing people into tribes and diverting them such that a critical mass opposed to the system itself doesn't actually happen.