Sorry, I mis spoke, down sized EGC. Typically I saw boxes fed from the top and the bottom unused clamp was removed they wrapped the bare wire around the screw and reinstalled the clamp. That was twisted tight to the outgoing RX ground (usually 2" or twist or more) and they left a stinger for the receptacle. The argument was the fillister head screw on the clamp was not suitable for a binding screw but using the clamp as a washer was OK.
