If you're willing to go through the paperwork and pay for the appropriate permits it's possible to legally own a lot of highly dangerous equipment. I think the

If you're willing to go through the paperwork and pay for the appropriate permits it's possible to legally own a lot of highly dangerous equipment. I think the only weapons that cannot be legally owned by civilians through any means are things such as nukes and chemical weapons. Guns are probably a sufficient deterrent against tyranny. A hypothetical tyranical army is unlikely to just start bombing major cities and blindly killing civilians. Guns don't have to enable the citizens to win, they just have to raise the cost of victory high enough to not be worth attacking.