An ammunition feed system wherein a single layer of ammunition is conveyed in a magazine by two independent closed loop conveyors disposed side by side in parallel, serpentine paths. Live rounds are fed on parallel output paths into first and second expansion rotor systems which, in turn, supply the rounds to a pair of feed rotors which insert the rounds alternately into a gun feeding conveyor. Spent rounds are withdrawn from the conveyor by a pair of return rotors, which, in turn, supply third and fourth expansion rotors, which return the spent rounds to the first and second parallel serpentine paths. The feed and return rotors contain pockets for receiving rounds alternating with surfaces for guiding rounds and cooperate with the expansion rotors to double the rate at which ammunition exits the system over that at which it is transferred out of the magazine. Rounds are further positively guided by rotor guide surfaces and auxiliary guiding surfaces during handling by the rotor systems between the magazine and gun feeding conveyor.