Sorry Dodgeman..........but that isn't up to code either..........
Use a "greenie" wire nut:
Start with a long length of bare wire .......loop one end of the bare pigtail around the metal box/screw and tighten......
Bundle all grounds with the green wire nut and the long bare ground wire fits thru a hole in the wire nut........Use a needle nose to firmly attach the connector.........Then carefully push the connection to the back of the box leaving the other bare end of the pigtail to attach to the device..........