Ha, well moving its not an option, as its Federal mandate across the pretend to be free land of Canaduh. So in the words of cpt Dale Dye in movie Platoon.
Where are you going to retreat to? You have to fight, and that's means you lieutenant.
Well, if I can only have one gun, then I am going with my Sabatti 12 gauge O/U that I have owned since I was 14. It’s a gun I can use and know well, reliable, and versatile. If you only get one, make it something you can use for everything.
Strikes me that the thread veers between, "if you can have any one gun on the planet [are there guns on other planets? Make the question more concise: e.g. "if you could have any gun--presumably one you do not already possess, but perhaps not?"] what is it/ would it be?" To "if you could only have a single firearm"... Which is certainly not the question asked... Thread drift...
Ah, what the heck. I would venture that a nice condition 4T with all the correct issued components and the crate would be nice. A Custer era papered Springfield trapdoor would be nice also. I probably would not even shoot it.