Anyone who lives in the US can own whatever gun they want..

not entirely true.. a convicted felon, in most cases, is not allowed to own a firearm, though there are a few exceptions to this rule.

also, if a person has been admitted to a psychiatric hospital or other facility, even for one minute, they are not allowed to purchase a firearm for a period of five years.

convicted felons are generally not allowed to purchase or possess firearms, but they are in some states allowed to purchase black powder revolvers and rifles.

i even find it odd that one can walk into a cabelas store and purchase one of these black powder revolvers, and i understand that you dont even need to show identification to make the purchase.

https://www.cabelas.com/shop/en/pietta-1851-confederate-navy-black-powder-revolver