I have doubted the enforceability of this letter from day 1 for several reasons. This letter is also so ludicrous and full of holes that I have doubted its validity as well - I certainly hope nobody at the ATF was stupid enough to write such a letter.
The assault weapons ban does _not_ have any provision for the loss of pre-ban status but it's _only_ requirement for grandfathered status is that it was a SAW before the ban. The rest is merely speculation on the ATF's part. The ATF has piled interpretation over interpretation in an attempt to make a new law. This doesn't fly. The AWB only requires:
"(2) Paragraph (1) shall not apply to the possession or transfer of any semiautomatic assault weapon otherwise lawfully possessed on the date of the enactment of this subsection.
The definition in the AWB of a SAW does _not_ say it has to be capable of semi-automatic fire. It says:
"(B) a semiautomatic rifle that has an ability to accept a detachable magazine and has at least 2 of--
First lets dispell the word "rifle". By definition:
RIFLE - A weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed metallic cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger. 18 USC
A lower receiver that is designed for these purposes is considered a rifle. And as we know, the lower half is considered a firearm by the ATF just as an M16 lower is considered a machine gun and will get you 10 years at club fed. Just as a lower with full-auto parts makes it a full auto firearm, a lower with semi-auto parts makes it a semi-automatic firearm. If you had a post-ban lower with a collapsible stock on it, the ATF would most certainly bust you. Make no mistake about it. The upper is irrelevent if it has 2+ assault features on the lower because no matter what upper you choose (pre or post ban) it is still an assault weapon.
Regardless of this, though, one who is paranoid has several different loopholes to consider. Also consider that the letter said it would lack the necessary _components_ ... they didn't say "was not fully assembled into a firearm capable of firing rounds". I suspect that this letter was in response to stripped lowers, as the wording of the letter suggests that a lower with a collapsible buttstock and pistol grip could have the necessary "components" to make a SAW...but that's irrelevent as is this whole letter.
First of all, even though [Joe Bob's Rifle] was not named by manufacturer, the following terminology is used in section 1 of the AWB to name all AR-15 clones:
(A) any of the firearms, or copies or duplicates of the firearms, known as--
"(iv) Colt AR-15;
Since Colt is the patent holder for the AR-15, any other AR-15 clone is considered a 'copy or duplicate' of it thus is technically covered under section 1, and would have the same "pre-ban" protection that a true Colt AR-15 would have.
So it is fair to say that the first section names all AR-15 clones, and that the sections thereafter are designed to catch any designs (and not manufacturers) not listed.
Next, the ATF has alredy ruled that if an individual had all the parts in their posession to build a SAW before the ban, they can legally assemble the pre-ban. So if you already own a complete pre-ban and are replacing components (even a lower), the ATF would have to contradict themselves to say it is illegal.
Finally, since breaking down your AR-15 for cleaning doesn't cause it to lose its pre-ban status, the lower you're thinking about buying is still a SAW if the dealer still posesses all the parts to make it a complete SAW (who doesn't) - it doesn't go into someone else's POSESSION until it is transferred to them. So if you want to buy it, and it does have grandfathered status, either send your upper half to the dealer, or bring it with you when you transfer it. Posession is OWNERSHIP and not LOCATION. Being in a UPS box is no different than being in my own personal storage, or in my safe. Otherwise it'd lose it's preban status if I mailed the lower in to get refinishes. Being _shipped_ as just a lower does not make it lose its pre-ban status, so if you're this paranoid just make sure of two things: 1. the dealer still has all the parts to assemble it in pre-ban configuration, and 2. you put your parts on it before you transfer it (technically you're selling your parts to the dealer, and then those parts are acting as replacement parts, then he's selling you the whole rifle).
As I said before, however, this letter is complete BS and unenforcable at that. Despite what the ATF might _think_ they are _not_ the legislative branch. Nevertheless, I sure wouldn't want to be the one to test this in our biased legal system.