Notes on automatic fire.

In this essay we examine automatic fire independent of platform. A heavy machine gun then is properly compared to a crew served weapon that has to fire from the ground or other stable mount – perhaps a 37 mm infantry gun. Automatic fire then is understood then as a trade of size for numbers.
There is no point to have a round that is any larger than necessary to destroy or disable your target. Thus a heavy machine gun is usually more useful than a small infantry gun because most targets are personnel
Automatic Fire has three purposes
1. Mowing down compact groups.
2. Decrease aiming requirements via ‘burst’.
3. Provide suppressive fire in conjunction with maneuver.
Opponents will adapt to 1 by dispersing their formations. Then the power of automatic weapons rests on 2 and 3 as a semiautomatic weapon can kill just as easily as an automatic one. The multiple bullets does not really allow the automatic rifleman to engage multiple targets as it must aim for each target. Tracers are an exception to this, but as they reveal the automatic rifleman as much as reduce aiming requirements they are best used in asymmetric situations (such as vehicle mounted weapons against dismounts).
Burst fire reduces the aiming effort of the user. He still must aim but he can take less time doing so because he has a spread pattern that allows him to aim with slightly less precision. This means that he can hit momentary targets, such as someone darting from cover to cover, more often than a semi-automatic rifleman. Also the user can make a horizontal ‘line’ across the target compensating for aiming uncertainty and increasing the overall chance of a hit. Burst of course reduces but doesn’t eliminate aiming.
Returning to the case of the small infantry gun v. a HMG, the SIG may have exploding rounds which might decrease its aiming requirements as well. In practice however this requires the detonation to occur at the right time in the flight path. That requires either precise fuze setting, or for aiming at something that will cause the explosion in the area desired. In other words the time and trouble to aim is effectively increased, not decreased. Thus HMGs are more useful than SIGs except in some narrow circumstances. An advanced automatic aiming system, such as the XM-25, increased the relative usefulness of the big rounds. It is our opinion however that an even more advanced automatic aiming system would be needed to make a SIG generally more useful than a HMG. A shotgun approach would reduce aiming requirements but this prevents rifling and reduces range negating the benefit.
The German army in world war 2 incorporated the ‘burst’ advantage into their doctrine and developed a number of weapons with extraordinary high rates of fire such as the MG 42. These high rates of fire were fine for bursts because the overall rate of fire could still be kept low, but the probability of hitting a momentary target is that much greater. The best example of this was the However most General machine guns have a more moderate rate, reflecting an understanding of the 3rd advantage of machine guns. The arena where this doctrine was most successful was their MK 108 auto cannon. It appears that in dog fighting there is no suppression and burst is the main function of automatic weapons. Since world war 2 automatic auto-cannons in aircraft have increased their rates of fire, with the introduction of revolver cannons and the re-introduction of their higher endurance siblings the Gatling cannon.
Suppression is using firepower to not necessarily destroy targets but to temporarily neutralize them. An automatic weapon is fired at the area where the enemy is known to be present. This forces the opponents in the area to take cover and prevents them from aiming or moving. The purpose of this is to allow friendlies to maneuver with much reduced enemy fire while they are exposed.
Suppression was not well understood but the logistical downside of spraying an area was which is the reason that armies were so slow in adapting automatic weaponry.