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.
How would that even work if the state already has a monopoly on military firepower (not just some rifles) and the proletariat is armed and ready to defend their rights (irrespective of their social attitudes, when push comes to shoves no prole will voluntarily give up their salary, benefits and good workplace conditions when they can physically defend all of the above against some wannabie capitalists or whatever)?
The only way this would work is if the military does an 180° turn and decides to coup the government and install a counterrevolutionary regime, in which case the workers NOT having guns would not prevent the counter-revolution.
All in all there are zero downsides to instilling a spirit of revolutionary militancy in the populace, training and arming them and letting them defend the gains of the revolution how they see fit if the worst comes to worst. On the other hand lulling the workers into a sense of false security, that the "wise men" in central government know best and are keeping everyone safe is inviting disaster by robbing the entire citizenry of initiative and pre-emptively paralysing any revolutionary defence they could mount (as happened in the USSR and the rest of the Eastern Block).