So if there were a “War on Guns” in the US, do you think it would be targeted toward “rural America” or the “inner city”?
Practically speaking I think this is unlikely to be possible in the US. Banning guns would be a dead letter law. Guns are so widely owned and pervasive it would be impossible to implement. I expect law enforcement won’t want to get involved either due to how dangerous disarming an entire populace would be.
Ban manufacture and sale to any party but the US government and let entropy do the work.
But the conclusion remains the same in that making a working firearm at home isn't difficult, and there exist a plethora of designs like the FGC-9 family that can be assembled from easy-to-acquire parts, no manufacturer needed.