You honestly think you can defend yourself from tyrannical government with a a couple pistols and rifles? That may have worked in 1776, before the wide, potent, and high-tech array of weapons US forces have at their disposal. Small arms are a joke in comparison.
Who painted that scenario? Why did your head go there? Either way I'll bite. History has proven (again) Revolutions can and do work. There won't be one on American soil in our lifetimes, hell, a non military coup is more likely. We're civilized here. Back to the original point now, lets stay focused.
Natural Disaster = Government seizing your guns and ammo and c4.