Originally Posted by carbon15man
So by what you guys are saying I can get an complete lower with the rifle stock on it?
No, not unless it's mated with an upper with a barrel of at least 16". A receiver, even with a buttstock, is still transferred as an "other" on a 4473. The GCA rules are 21 and up with an exception for rifles and shotguns, not 18 and up with an exception for handguns. Since a receiver is not a rifle or shotgun there is no way to apply the exception. Your dealer could mate it with a rifle upper but he may need a 07 FFL and the sale will also be subject to the excise tax. IIRC, structuring a purchase so as to avoid the tax liability is tax evasion and can earn you and your dealer license plate manufacturing lessons courtesy of Uncle Sam.
Mated with a barrel of less than 16", a receiver and buttstock will fall under Title II (NFA) rules and cannot be transferred under Title I (GCA) regs. Title II is 21 minimum age, too.
It may be possible to buy a receiver in a private sale but I only have experience with C&R and Title I FFL purchases. Honestly, the BATF is very helpful with these questions and their documented response can keep you off the government "naughty list". I find that they are easier to deal with if you think of them as an extension of the IRS (as they were originally chartered).