I think the answer is that Hitler did not prohibit gun ownership except for Jews..
However, correct me if the following is wrong:
1) Josef Stalin, the sole leader of the Soviet Union from 1924 to 1953, said:
“If the opposition disarms, well and good. If it refuses to disarm, we shall disarm it ourselves.”
In 1929, the Soviet Union established gun control. From 1929 to 1953, about 20 million dissidents, unable to defend themselves, were rounded up and exterminated.
2) Mao Tse-tung, communist dictator of China said:
“War can only be abolished through war, and in order to get rid of the gun it is necessary to take up the gun.”
China established gun control in 1935. From 1948 to 1952, 20 million political dissidents, unable to defend themselves, were rounded up and exterminated.
3) Idi Amin, president of Uganda from 1971 to 1979, said:
"I do not want to be controlled by any superpower. I myself consider myself the most powerful figure in the world, and that is why I do not let any superpower control me."
Uganda established gun control in 1970. From 1971 to 1979, 300,000 Christians, unable to defend themselves, were rounded up and exterminated.
4) Pol Pot, who created in Cambodia one of the 20th century's most brutal and radical regimes, was responsible for killing one million of his own ‘educated,’ yet unarmed citizens.