The Halo 4 S.A.W. - the P-305 resembles a belt-fed version of this weapon.
"To Hell with 'short controlled bursts!' It's a recoilless magnetic accelerator with a continuous belt feed and a psychotic cycling rate - just fire! Fire!" - Anonymous Directorate Sergeant advising his squad's Automatic Support Weapon gunner
The P-305 Type-16 Automatic Support Weapon [305-16 ASW] is the Directorate's principle squad-level automatic support weapon. Like the P-220 Type-13 Rifle, the weapon is an induction coil gun and fires the same 12mm self-propelled high-explosive bolts. However, its barrel is considerably shorter, giving it less range and accuracy. Ammunition is fed by a long flexible ribbon feed running from the breech of the weapon back to a large electrically-powered drum worn on the gunner's back, providing a continuous stream of several thousand rounds.
Firing Mechanism[]
The 305-16 has an extremely high rate of fire, about 2,500 rounds-per-minute. When it fires, the muzzle reports of each shot become an indistinct blur. If the gunner lightly squeezes the trigger, the gun unleashes a high-speed five-round burst, though it sounds like a single shot. If the trigger is held down, the weapon will fire continuously until the firing mechanism overheats or the ammunition runs out. A holographic blue panel projected atop the weapon over the stock indicates the heat level of the weapon. As the gun fires, the panel turns purple and then red, and once sufficient heat levels build up it stops shooting while the heat sinks cycle.
Additionally, the weapon's computer programs the flight path of each bullet in a 5-round burst, so that each one of them hits the target in a slightly different location. Thus the automatic fire is actually a series of very rapid 5-round bursts, although the speed is such that it sounds like one continuous whirring sound.