I called and spoke to Dan at D&D. He said that the plans are for milling a stamped reciever to clean it up use, and that it is what their machinists use between stamping and welding and between welding and finishing.
NYTahoe
Please keep us informed; would appreciate any information on whatever progress you make with your 80% receiver. I have one also but haven't done anything to it yet, thanks.
Paul