What in your mind is a limit? EG, I can own and operate a car in all 50 states + a pile of other countries with a US driver's license issued by my home state. For the most part anyone can get one, though you can lose the right if your an idiot... ie bunch of DUIs.
Also there isn't a constitutional right to drive, I can see that one both ways, what are your thoughts?
[Not meant to be argumentative]
Types of weapons limit (automatic weapons, suppressors, etc..). People limit (felons, concealed carry, etc..) Purchase limits (waiting period, background checks, etc..)