Now let’s look at the question of justice and the right to bare guns.
When the USA Constitution was written, it made sense for people to have weapons, because there was no justice, police and what ever makes nations save to normal people. So everybody needed the right to protect one self. Things have changed in between. There is a justice, and plenty of police in many varieties in the USA. So, actually there is no more need for self justice.Looking at Germany where there is no more Kaiser / King to rule the country, and the dictatorship has ended too, so laws had to be adjusted. Not only was it necessary to create new laws, but also to rewrite the fundamental Constitution to fit the new democratic country. Of course loosing the war, set a changing point, and put the winners into the position to tear up the old german laws.
But this made Germany a country with a modern Constitution, set up for the 20th Century. Mean while the USA, the winner of the World War, had no reason to rethink their Constitution, and got stuck with obsolete passages in their Constitution.
Combining this with the thougth “I have to be responsible for my entire life” lets US citizen realy beleave, that they need to protect themselves with weapons. They will not allow the authorities to be the governance. Obviously the US citizen do not trust their government to be the only force within the country.
Germany, as well as the rest of Europe, have experienced so much grief do to weapons, and have such a high density of population, that having free access to weapons is a high risk to public safty. Besides loosing a war helps, everybody not being happy with seeing Germans handle weapons.
So in Germany the only people carring weapons are government officials. Also Germany being a country with a high regualtion of the daily life, has set up many rules to make sure only those people realy needing a weapon will get one after they have proven to be capable to handle a weapon. Simply you need a license.
If you need a license to drive a car, how much more sense does it make to make sure who ever is handling a gun, has the mental abillity to do so.
Now in Germany the government has a high impact on regulation, like everyone in Germany is registered where he is living, so it is very easy to find someone and keep track of the person.
Again Germans leave a large part of their abillity to rule their own life as they will to the government, in favor to a organized and justice life.