The correct reason for any an all guns is because it is a right. No one needs or should have to justify a right. If it required justification it wouldn't be a right

Why do you need cars? You've got two legs already.

Every boy needs a toy or two or thirty.

Cuz when you live alone and there's a surly creep working on the neighbor's yard...

Also, for fun :)

Guns are one thing, getting away with murder every single time now that's something

AK does it all