I need a gun to protect my house
Nah, just some beartraps, pits with spikes, huge rolling boulders, snakes (why does it have to be snakes?!?) and such.. And I really think you're going to need them, as your collection might actually be more attractive to archeologists than to common thieves
And guns are for killing, be it game or people, protection comes trough various means, none which need to be lethal. Just my opinion, feel free to think differently...