Defense Distributed has come out with an inexpensive miniature CNC for milling 80% lowers. Similar in size to a Makerbot, the Ghost Gunner CNC can easily sit on a desktop. They have pre-orders up now. Only about 63 orders left at $1199 per machine. Like all Defense Distributed projects, the Ghost Gunner is open source. DD says the Ghost Gunner is rather easy to use.
If you can assemble a firearm or operate a 3D printer, you can use Ghost Gunner.
Ghost Gunner ships fully assembled and ready to build right out of the box. No assembly is necessary and no programming is required. After installing the included software, you’ll be ready to manufacture publicly available .dd designs. Defense Distributed is committed to releasing future firearm design files, from the AR-15 to the AR-10 to the 1911, and then continuing with our own designs.