 Upon return of the barrel to the forward position, the energy stored in the intermediate spring cycled the bolt back and forth, extracting and ejecting the spent case and feeding a fresh round into the now stationary barrel.The main goal was to achieve smooth and reliable cycling, but the design was very complicated and thus badly suited for a military firearm.By 1911, Farquhar and Hill revised their rifle, changing its source of energy from barrel recoil to more convenient gas operated action.