Fighting for ideology, nation, protection of own house/ family - those are the reasons.
Some revenge, historical chance.
But dying for the confiscation of small arms not many people would found worth.
Let's imagine. Ok, we are the "gun people (GPstan)", and we want to - what?
Follow us, give your lives and your sons for GPstan and you will - have the right to own a gun?
How many followers could they gather?
In reality, those things have great inertia, thus there will probably be some process of making it more difficult to get the guns. Or there will be some option to give the gun voluntarily.