Why the scanner crew used a shotgun for the famous exploding head scene

Dupuis revealed that they had several different fake heads that they tried to blow up using different methods, including a plaster head, a wax head, and the gelatin head used in the final film. According to Irwin, they filled the heads with “clam macaroni and vermicelli” and fake blood before blowing them up, but the problem was that every time they used a detonator (a tiny explosive), a visible spark was created. Since the explosion was supposed to be entirely due to Revok’s mind powers, a spark or smoke would ruin the effect. Dupuis explained:

“When it exploded from the explosives, it created an enormous cloud of smoke. And it looked more like the Death Star than an exploding human head.”

So instead of putting explosives in the fake head, they decided to use something else: the explosive power of a shotgun blast from below. Shotguns are extremely destructive, especially at close range, so it was a dangerous but effective idea. Dupuis and Irwin said that effects coordinator Gary Zeller crawled under the dummy version of Louis Del Grande, pointed a double-barreled shotgun at the back of the head and pulled the trigger. The result is seen in the film, and it is frightening.