When the full auto AR-15 blueprint comes up, let me know.
There's already a CNC data file for the AR-15 lower receiver (sans auto sear pin hole) out there on the internet. Download it to a flash drive, grab a chunk of aluminum and pop in to a place such as TechShop, et voila!
An AR lower is actually a very interesting project for the 3D printer. There are companies already making them out of polymers, so...
Will you settle for a 3D-printed semi-auto AR lower?