In addition to The United States, here are four other countries where you can own arms:
The Swiss are not only allowed to have guns, but many citizens were traditionally required to own one and go through training on how to use it. Switzerland’s laws require having a permit in order to be able to buy certain firearms, and these are attainable relatively easy.
Swiss flag image courtesy of Wiki Commons
Czech Republic is another place in Europe where you relatively easy can get a permit for gun ownership, also for most foreigners who live there.
There’s no limit to how many firearms you can own and you can carry a concealed firearm.
Private possession of a large variety of guns is allowed for Estonian residents under a license. These can be obtained for any number of reasons, including self-defense.
The government maintains a record of individual civilians licensed to possess firearms and ammunition, but private sale and transfer is allowed, as is concealed carry.
Most types of firearms can be legally purchased in Paraguay, but a license is required and a central registry of gun ownership is maintained.
Even as a tourist you can legally buy weapons in Paraguay.