This may mean that gun control simply fails in non-authoritarian countries, and they either go authoritarian or increasing live without effective controls on guns.

Yes! This isn't limited to gun control either. It's a politico-technological arms race.

People develop technology that subverts the government. New laws are eventually created, allowing the government to adapt to the new technology. With each cycle, the government must become increasingly tyrannical and totalitarian in order to maintain its own power over the governed population. We'll end up with either an uncontrollable population or an absolute state.