This was performed and filmed in the Basilica of Koekelberg in Brussels, Belgium.
The General Electric GAU-8/A Avenger is a 30 mm hydraulically driven seven-barrel Gatling-type cannon that is typically mounted to the United States Air Force's Fairchild Republic A-10 Thunderbolt II. Designed specifically for the anti-tank role, the Avenger is extremely accurate and can fire 4,200 rounds per minute (=70/s) without complications.
Astronaut Charles Duke (1972, Apollo 16) dropped a hammer and had the hardest time picking it up.
it was no simple task, they had to build a box strong enough to protect the camera.