80% lowers have been around for a while now. In some areas like California if you finish one, you have to apply for a serial number, pay a fee, and then engrave the finished lower.
The term 80% lower or frame comes from a BATFE determination that it isn’t a firearm if it is only 80% finished. Thus, there is no NICS check on an 80% lower or frame and it can be mailed to you. Given it was a determination by BATFE, you know it can be changed at any time.
Here is an alternative.
You say it is only a chunk of 6061-T6 aluminum. Not so fast. According to the manufacturer, it is the 0% billet AR-15 lower receiver. It helps to have your own CNC machine or a Bridgeport milling machine. I guess you could go all Khyber Pass and finish it strictly with hand tools. Both methods are beyond my level of skill so I’m stuck with off-the-shelf lowers from Aero-Precision, Anderson, or Spikes.
The manufacturer, 80% Arms, adds that they are restricting sale to the USA only.
While these weapons are not regulated under ITAR yet, we still don’t want these dangerous things to get into the hands of the wrong people, like Kim Jong-un. Therefore, shipping of 0% lowers is strictly limited to USA only.
Well played, sirs, well played.