from what little material I can gather , it appears that they built as far as possible a 'working' platform based on 9MM that could fire as the script called for, full auto , single shot etc including servo controlled gun barrels 'telescoped' inside one and other that "responded" to the voice control , like the original Lawgiver 1 but with a LCD display that worked so that they could film the Hero on set 'live' without a lot of SFX set up , certainly in the interviews all the actors stated they could fire the guns on set