I got several questions about this today, and I thought I’d clarify. As of November, you must be 21 years old to receive a frame or receiver for a firearm. It doesn’t matter if it’s to be used to make a rifle or a handgun; it’s now treated in a similar manner as a handgun.
Congress didn’t pass a law while we weren’t looking, nor did the ATF sneak a regulation in under the radar. This is simply a clarification and enforcement of a clause buried in Code section 922, which states:
[It shall be unlawful for any licensed importer, licensed manufacturer, licensed dealer, or licensed collector to sell or deliver] any firearm or ammunition to any individual who the licensee knows or has reasonable cause to believe is less than eighteen years of age, and, if the firearm, or ammunition is other than a shotgun or rifle, or ammunition for a shotgun or rifle, to any individual who the licensee knows or has reasonable cause to believe is less than twenty-one years of age
Receivers were never explicitly targeted previously, but as per a letter sent out last week (pdf):
A frame of receiver is a type of firearm “other than a shotgun or a rifle” and the transfer by the dealer to an individual under 21 years of age would be prohibited by Title 18, U.S.C., section 922(b)(1).
The letter also states that an FFL may not sell a frame to anyone under 21, nor to unlicensed individuals from other states. Essentially, if it’s not a shotgun or rifle, they’re treating it like a handgun.
All of which scotches the idea of anyone under 21 building their own rifles.
The worst part is that there’s no real way around this. The ATF has chosen an unjustly strict reading of the code, but it’s all there. § 922 is pretty much the omnibus of modern gun regulation, and challenging it would require a massive effort.
This could be a shot over the bow in reaction to the Firearms Freedom Acts passing in several states, but if so, it simply proves the need for such acts in the first place.