As a private individual a fully automatic gun made after 1986 is illegal for you to own. Its part of the hughes amendment.
There are post year 86 machine guns, called dealer samples that are still manufactured and floating around, but they can only be owned by a law enforcement agency or a class 3 firearms dealer. Not private individuals.
This is probably more a question for a lawyer than a rando on the internet, but how legal would this be: let’s say you have a rifle that was designed as a semi-automatic, but can be easily modified to become automatic and that was manufactured before 1986. Would it be possible to legally modify it in [current year] to be an automatic?
We’re getting pretty deep in this comment chain, and I appreciate you letting me pick your brain over this. Usually people abandon threads way before this mark and just wanna give a shout-out for your time.
The way the hughs ammendment works is, the only legally transferable machine guns were those that were on the registry in 1986. The total number of those registered machine guns was 175,977. There are no more. If your gun was not on that registry when the hughs ammendment passed, the answer is no.
But… god these rules are ridiculous.
For certain guns, if you have a legally registered full auto sear (the sear in this case is the firearm), you can put that in the appropriate nfa registered firearm (think sbr), anf then it would be legal.
This is normally how you see fully automatic hk95 and mp5s and registered colt recievers put into modern ar15 platforms.
It really is a shitshow when it comes to these laws. The real answer to all your question is money. If you have the cash equivalent to a brand new vehicle just sitting around, you can have a legal full auto gun. If you dont have those funds, dont bother. You wouldnt be able to afford the ammo for a fully automatic anyways.