Have you been to America? It's easy to think 'oh, they are more or less like us' but they're not. They're a totally different people.
Every time I went I went to a game and they will all stand on command and sing their anthem and they take it very seriously. The first time it reminded me of North Korea and the way they behaved in documentaries I'd seen.
They are told they are the "land of the free" and they believe it wholeheartedly, but in reality they are quite totalitarian. For example,
If you choose not to have your baby circumcised they inform child protective services.
They do have much freedom of speech but not against government, they have FBI visits for facebook posts, we would only really send the police round.
The guns represent freedom, individuality, and in the constitution it states they are for protection from a corrupt government.
Now this is where I see where they are coming from. If the guns are said to be there to protect you from government, who is the very last body you would give them up to? Who is the very last body you would listen to around removing that right?
And how far can you dispute this when the government has harmed its own people multiple times?
They can ask for amnesties but even though morally it makes sense you can't refute the argument for them. They will not give them up voluntarily. There's not much the government could do except keep piling on the pressure and guilt.