[Organic Panic]

All you get with one of these builds is a lower receiver without a serial number. I fail to see how that is such an advantage.

Very true. But until the ATF raids every supplier of barrels, bolts, and receivers the firearm will remain hidden from their grubby hands. I have a full machine shop and parts are no problem for me or any reasonably supplied hobbiest. But it is a very specialized shop that can produce barrels. I am sure the ATF is being directed to go after barrel manufacturers. It's only a matter of time.

[GingisK]

I have a full machine shop...

Me too. I'm doing a lot of study related to barrel making. Soon I will start experimenting with those processes. Surely I have an advantage over those who made barrels in the 17-1800s.