I think this is the most likely. Either that or defining down the 80% lower to something short of a hunk of metal. There are also non-AR15 pattern "80%" receivers out there, for Glocks I think.srothstein wrote: ↑Fri Apr 09, 2021 8:37 pm I believe the specific case that Biden referred to, and that touched this all off, was that a company put together kits that had everything needed to build a complete firearm with the lower being an 80% lower. It included all the interior parts for the lower, the barrel, slide, etc. I have a vague memory of ATF raiding a store front doing this and selling the kits through the internet. I do not think they were breaking the law but they sure pushed the limits of it.
I am sure that the only way the ATF can do anything is by defining a ghost gun as a kit that can be used to assemble a complete firearm that has a partially milled frame. If they do anything else, they will kill the used and accessory parts market (which I doubt would bother them other than their losing the cases in court). If they try to define an 80% lower, people will go one step further from complete and sell 75% frames, ad infinitum. This can only result in defining blocks of metal as firearms and that won't fly either.
I predict that some definition of a kit to make a firearm will be created and then banned (well, maybe just defined as a firearm and the dealer would have to be an FFL and run a background check, which implies a serial number on the frame). Even this is pushing the limit of the law, but would be harder to find someone to fight it in court.
Another angle might be to require a serial number on home built guns then require any further transfer go through a FFL. Contrary to current internet wisdom, it is NOT illegal for a private individual (non-FFL) to transfer a home built gun intrastate to another individual.
And currently, though ATF tries to say otherwise, no serial number is required for a private transfer. There is an article out there where the author gets the ATF to admit this in a private letter. More importantly they are unable to cite the law or CFR requiring an individual privately transferring home made gun to add a maker and serial number (like you HAVE to do for NFA Form 1 builds). If you think about it the serial number in this case would be useless since there is no record of it anywhere, where there is for a FFL Manufacturer made gun that they report upon making.