I fell in love with gatling gun scenes after this...

Jesse Ventura became the first actor in cinema history to fire a hand-held Gatling gun.
He mentioned in an interview that a power cord ran from the gun, down his pant leg, and to a prop guy out of camera view who touched the ends to a car battery to power the thing.
Bill Duke became the second actor to fire the weapon on screen, and Stallone would have been the third in the last Rambo movie, but the gun was too heavy for him. Sly reportedly was able to hold the gun, but couldn't maneuver it quickly enough for the scene's requirements.