As far as I know, all of them - USSR, Cuba, China, Vietnam, NK etc, implement gun control. Why should their governments do that? The people of these states genuinely support(ed) socialism, if they are/were all armed they can protect socialism far better than the 1% of the population that makes up the military.
Therefore, they are not democratic.
it is democratic when the communist party does it, because the communist party represents the people.