Hm, I thought I read someone on AR-15 about it needing to be registered at the manufacturer. So basically as long as the FFL transferred it as a pistol/receiver/other I should be all set? Of course I don't know why I'm trusting a forum for this kind of legal advice, lol. I guess tomorrow will be read the BATFE firearms regulations.
First of all, manufacturers don't register any firearms, except NFA items, with the ATF. They must provide a yearly report of the number of firearms made, which is how their excise tax is calculated. They can report Shotguns, Rifles, Handguns and Other. A stripped receiver is Other. It is a Title I firearm. There are a few other things that can end up in the Other category, for example 1919s in A4 configuration, breach rings for artillery pieces, etc...
If you're buying a stripped lower, and the FFL reports it as anything other then a stripped lower on the 4473, they are also breaking the law. A good FFL is smart and does the right thing when it comes to lowers. If a lower comes in that has a paper trail of being stripped, and is still stripped, they should log it in to their bound book as a Stripped Receiver. If there is some doubt, or the lower has a stock on it, it should be logged as a Rifle Receiver. Only complete firearms should be logged in and out as Rifle or Pistol in the bound book and on a 4473. For example, once you've assembled your pistol, if you where to trade it in, the dealer should log it as a Pistol.
The manufacturers that are marking lowers as Pistol are really doing the world a disservice. What's to stop me from buying one of those lowers, and assembling it into a rifle? If I did that, then stripped it down and sold it off, and someone later assembled it into a pistol, they would have committed a felony without even knowing it, and they would think they are totally in the clear. Granted it would probably never cause the owner a problem, but if the ATF ever did a trace on the serial number, if the gun was later used in the commission of a crime, for instance, and it came back to me as having once owned it, and I had filed a FA-10 saying it was a rifle, BAM!
--EasyD