The weapon itself has three firing modes: semi-auto, full-auto at 460 rounds per minute, and three-round burst at over 2100 cyclic rounds per minute, or approximately 36 rounds per second. The loading and feed mechanism is physically very complicated but exceptionally fast and reliable. Rounds are fed into the weapon from a magazine that lies above and parallel with the barrel. The rounds are oriented vertically (at 90 degrees to the bore) and are fed downwards into the rotary chamber so that they can be rotated 90 degrees for firing. The firing cycle process is roughly: