Originally Posted by SuperRTowner

With a real gun this is called Bump Fire. With a real rifle you have to fire from the hip to achieve it. The recoil energy throws the rifle back while it's in your hands, this acts like a runaway see-saw motion. as it converts back and forth from Kinetic to Potential energy it helps you fire the trigger again. While it's not as fast on a real rifle it's the same thing.