@⚸ยℓเtђ Full auto weapons aren't exactly easy to get. They have to be in the machine gun registry, which hasn't been opened since 1986. So for starters, you can only obtain a fully automatic weapon that was manufactured and registered before then. Then there's the fact that a number of states just ban full auto anyways. Legal federally, illegal locally. What remains after that is a slightly more complicated background check than the usual form 4473 used for most firearms... although it's mostly just a matter of getting fingerprinted.

Realistically, you're only owning a full auto if you're rich... or if you're willing to break the law, since converting a semi auto is trivial.