Properties of the Machine-Gun
The effects of machine-gun fire, as with that of the rifle, depend on:
1. The rate of fire;
2. Precision of fire, meaning the grouping of the shots;
3. The tension of the trajectory (it being the same as the model 1886/93 rifle);
4. The regulation of the fire.
The rate of fire:
The rate of fire of the machine-gun is between 200 and 300 shots a minute, with the maximum rate being 600 shots a minute. This means that the machine-gun fires as many rounds as a section of 50 men firing at the rate of 6 shots a minute.
Precision of fire:
The precision of the machine-gun’s fire is approximately three times greater than that of a section of infantry. It is such that in a fixed fire at 1,000 meters, the width of the grouping of shots is between 3 and 4 meters, and that at great distances the depth of the ground that is struck by rounds is no more than 100 meters. (In other words, the sheaf of fire is narrow and deep) Additionally, due to the shallow depth of the sheaf of fire, the regulation of fire is obtained with a great approximation. An error of 50 meters in the estimation of distances gives an almost nil result with this type of fire. This necessitates a dispersion of the fire in order to help achieve the mowing effect, and the usual fire of the machine-gun is a free fire, at an average cadence with a back and forth motion.
Tactical Properties of the Machine-Gun*
Machine-guns fire the same cartridge as the infantry rifle, possessing all the same ballistic qualities. At the same time, its fire compared to that of the rifle provides essential differences.
It is much faster. Because of the stability of the mount, it is less affected by the nervousness of the firer. The direction of the fire remains at all times in hands of the commander. Due to the fire of the machine-gun being very condensed, it is able to produce in a very short time decisive effects on a given point. But in so far as the fighting troop, the machine-gun section which lacks the offensive capacity resulting from forward movement, can only achieve a close liaison with the infantry to which it supports.
Outside very exceptional cases, the use of machine-guns at great distances is not advantageous; the results obtained are not in proportion to the amount of ammunition expended. Lastly, in revealing its presence too soon, the machine-gun risks being destroyed by the enemy’s artillery for no gain. The machine-gun is above all the “weapon of average and short distances.” It usually works best when fired in short, intense bursts, executed as much as possible by surprise, directed upon strategic points in order to stop the enemy or to break his resistance so as to facilitate the movement of our infantry.
The machine-gun’s fire is particularly effective when it can take the objective by enfilade or by the flank. In this way, its fire can rake down the files of advancing troops and can create a barrier that the enemy is obliged to advance into. The machine-gun usually has little effect on thin lines or chains of sharpshooters spread out at great intervals. On the contrary, it can attack with great success all lively targets presenting themselves in at least somewhat compact order: unbroken lines, reinforcements, supports, reserves, counter-attacks, etc.
The best emplacements for machine-guns are on the flanks or to the rear of the empty spaces of the first line, when the ground has been prepared, which allow them to follow the stages of the fight and to intervene effectively by profiting from the infantry. Firing over friendly troops is only executed if the corresponding ground permits the establishment of two or more lines of leveled fire.
To sum up, the conditions in which the machine-gun is employed depends essentially upon the effects that can be produced . . . The machine-gun is the auxiliary weapon of the infantry in every circumstance of close-quarter combat. It remains in the hands of junior commanders: those of battalions and regiments. It is a reserve of mobile fire, flexible and particularly effective when it intervenes at just the right moment and on a decisive point.
Therefore, it is necessary to avoid revealing prematurely the machine-guns position and to group them together. They work most often by section, in immediate liaison with the infantry troops, amongst which they find favorable emplacements and convenient shelters.
Properties of the Machine-Gun**
The machine-gun produces a very effective strafing fire up to 800-1,000 meters; effective beyond 1,000 meters on objects of importance if the distance is estimated precisely. It is employed in direct fire at all distances, preferably at short or medium distances. Indirect fire is employed at medium or long distances.
There are three main principles of employment: flanking action, surprise, and echelon in depth. The sheaf of fire is dense, deep but narrow. Therefore, the maximum effect is had upon a target having a straight front and a great depth; for example, upon a thin line taken by the flank. The machine-gun fire which is parallel to the likely front of the enemy, in other words in a flanking position, must be the rule.
A back and forth motion must be employed when firing upon a thin line which comes abreast, but the density becomes insufficient and the effect produced is minimal.
Fire perpendicular to the front is only employed when sighted on the entrance to a straight passage and when coordinating [with other guns] in a concentration on a particular target. A machine-gun is easy to conceal. It must remain invisible, disregarding the targets which are not worth the trouble, then unleashing a surprise fire and thus obtaining considerable results. The obligation of echelon in depth is explained further on.Three principle employments: enfilade, surprise and echelon in depth.
The sheaf is dense and deep but narrow: the maximum effect is thus obtained against a target having a straight front and a great depth, for example against a thin line taken by the flank. The fire of the machine-gun parallel to the probable front of the enemy, that is to say enfilading it, must therefore be the rule.
The back-and-forth mowing motion must be used in order to fire on a thin line, but the density insufficient and the effect produced is low. [see fig. 280 above]
The fire perpendicular to the front is only to be used on the opening of a straight passage and to coordinate a concentrated fire on a particular target. The machine-gun is easily disguised; it must remain invisible, ignoring the targets that are not worth the trouble, opening fire by surprise and obtaining in this way considerable effects. The obligation of the echelon in depth is explained later on.Use of machine-guns in the engaged battalions
The machine-gun company constitutes an organic part of the battalion. It can only be withdrawn from an engaged battalion by the colonel, for a special, temporary mission which is of interest to the regiment. The battalion leader as a rule employs in his plan of engagement or his plan of defense. The machine-guns can be placed in the neighboring quarter if they are better off flanking their battalion to provide enfilading support. It is worthwhile to employ the two guns of the same machine-gun section close beside each other. If machine-guns are part of a combat group, they are under the orders of the group leader, whether he be a gunner or not. The machine-guns which support a unit in the offensive can be placed under the orders of the leader of this unit.
In principle, the machine-gun company commander remains nearby the battalion leader, in liaison and in frequent contact with his section leaders. He is responsible for putting unengaged sections into action and ensures the resupply.Use in the offensive:
Possible missions of the machine-guns of the attacking battalions:--To support the opening, then the progression of assault waves;
--To neutralize the known or suspected emplacements of enemy machine-guns;
--To cover the flanks of the battalion;
--To occupy an interval which is created between two units of the advancing battalion;
--To occupy conquered ground.
--To break enemy counter-attacks;
--To contribute to the retaking of contact in open ground.
These diverse missions require a large echeloning of machine-guns in depth: surveillance machine-guns fire at the opening of the action; immediate accompaniment, attack machine-guns, penetrating into the position following the attack waves and closing up as much as possible with them; available machine-guns, progressing in front or behind the battalion reserve company.
The MG sections keep in close liaison with the units that they are supporting and look to intervene spontaneously to their benefit or to the benefit of neighboring units. During the halts and on the conquered positions, they set up in checkered plan, echeloned in depth, utilizing rises in the ground or shell-holes in the open ground from where they fire by enfilade and by surprise. Yet they do not hesitate to set up in the open if necessary, notably to check counter-attacks. However, they only draw on the minimum number of servants necessary, keeping the others under cover.
Possible missions of the second-line machine-guns:--To support the flanks of the attacking battalion;
--To directly support the attack, if it is possible by firing over the assault waves;
--To eventually form with other detachments the garrison of the departure parallels (trenches).
Use in the defensive
The conditions of echeloning in depth, enfilading and surprise must be especially created in the defensive. The barrage obtained by the infantry’s own means must be able to create a front that is impenetrable even if an artillery barrage is not provided. Moreover, if the enemy, having destroyed a part of his means, has penetrated into the position the artillery is at first powerless to stop a closer barrage or to support counter-attacks. The role of immediate interior-zone barrages can only be filled by the machine-guns, and this is the principle reason why their echeloning must be done in advance.
The plan of action for machine-guns, inserted into the plan of defense of the anticipated quarter, details all their missions. These can include:
--Counter-preparatory fire, doubling that of the artillery
--Barrage fire, forward of the front or inside it
--Supporting immediate counter-attacks
The plan of defense of the sub-sector sets the barrage missions to be carried out, along with what benefits neighboring quarters if need be.
Allocation of machine-guns on the ground
In principle, never place machine-guns in the principle parallel (trench) or in its immediate proximity. They are in too great a risk of coming under the enemy’s preparatory artillery fire.
The reality, in general, is that machine-guns very seldom can be assigned to the flank of the principle parallel (trench), in light of the obligation of setting these guns up only behind the elevated sections of ground. The best conditions are if a certain number of guns can give a continuous and impenetrable barrage in advance of the front. Too much is unknown, but in general, and it falls to the accompanying automatic-rifles and mortars to help in creating the barrage.
The interior-zone barrages are carried out in the zones or obstacles which are meant to delay the enemy, as well as on the routes into which the layout of obstacles channel the enemy. Finally, they must offer immediate support to counter-attacks setting off from the support line to make progress easier.
A gun can thus have the following missions:--A defined barrage mission in advance of the front;
--A possible combat mission in the interior-zone of the position;
--And sometimes a third mission as anti-aircraft piece.
The battalion leader seeks out how to best utilize his machine-guns in the zones that artillery can not be relied on; creating dense barrages, based off the lay of the ground. Conversely, the colonel asks the artillery to provide a denser barrage in the zones that the machine-guns can not cover.
To avoid exposing machine-guns to enemy artillery:--Keep visible gun emplacements, on which a systematic destruction fire can be directed, at further distances away from the front;
--Conceal guns in covered or camouflaged positions (shell-holes, woods, ruins, camouflaged or underground access routes);
The shelters must allow for observation. They must also permit the gun to open fire very quickly in case of alarm. The reinforced casemate offers the best solution avec a small relief. If the rest emplacement is an underground bunker, the time necessary to reach the firing emplacement is to long. Therefore, organize next to this one a reinforced ready-shelter for the gun and its servants.
The machine-gun breastwork described on page 99 [fig. 59] is only used in rapidly constructed emplacements made during an advance, or for supplementary emplacements dug under camouflage.
It is convenient to number a unique grouping (M1, M2, M3, etc.) of the same sub-sector.
It is essential that all emplacements prepared for a machine-gun in some way very clearly indicates the fire sector of this gun. To do this, drive three heavy stakes (2.5-3 inches in diameter) into the gun platform, with each projecting out roughly 4 inches. One of these stakes makes up the apex of the angle. The two other stakes make up the two sides of the angle, one marking the most extreme left point of the gun’s zone of fire and the other marking the most extreme right point of the zone. Thus, the machine-gun’s complete zone of fire is made. These stakes are not in any way intended to act as the tripod for the weapon. Rather, they act as an easily understood reference at one’s feet, particularly needed at night, indicating how the fire sector is oriented and how large it is.
Each emplacement must have clear, concise orders providing (with the aid of a sketch):--The direct, indirect or anti-aircraft fire missions;
--The signal at which each of these fire missions is opened up;
--The elements of each intended fire mission: elevation, direction, mowing, duration, rate of fire (cadence);
--In the sketch: the locations of the infantry sections emplacements that will benefit from the barrage fire, as the case may be, pointing where the signal will appear requesting it.
There must be a liaison and a complete understanding between the two machine-gun section NCOs and the NCOs of the combat groups in front of which and over which the machine-guns fire, just as it is maintained between battalion and group artillery.
In general, the signal “Request for artillery fire”; which is only made in cases of serious threat, automatically unleashes barrages of 75s, machine-guns and automatic-rifles upon the entire front of the alerted quarter. It is easy to give a sub-quarter or a section of the first line the means of instantly unleashing only a machine-gun barrage and contained to only its front. This section lights a bengale (ground flare) or a special rocket (different from the barrage signal rocket) on a certain agreed upon point, well marked out by the machine-gun sections. The barrage fire of each machine-gun section is prescribed in advance. At the sight of the signal, these machine-gun sections open fire on their own. The duration of their fire is agreed upon (a few minutes, normally) or a different colored signal is given to cease fire.
The other machine-gun sections of the same quarter relay that the direction of the bengale signal isn’t the one which corresponds to them, and does not open fire. This method allows for action to be taken instantly against small patrols, work parties, etc., spotted by company look-outs and, in general, on all unknown or limited targets against which a barrage fire would be completely unjustified.
Indirect fire is only a checking procedure allowing an extension of the machine-gun’s field of fire up to 3,500 meters. It allows the gun to reach distant, defiladed targets, or for it to be carried back to a less exposed zone in the rear where it can fire over friendly troops. However, the impossibility of observing where the rounds fall, and the considerable dispersion over a great distance of these rounds, must be compensated for by employing the guns en masse and sustaining a prolonged fire. Therefore, it is necessary to assemble many machine-guns, which permits only opening fire at the same time as one gun out of two. To constitute this temporary formation, the infantry division commander assembles under the orders of the divisional machine-gun officer the machine-gun companies or half-companies attached to the unengaged battalions and machine-gun companies. This officer receives from division the “employment plan” of the formation. It remains with division and is relayed to the machine-gun companies under its orders by special telegram and, if need be, by runners, optics, etc.
Limits of use
Safe distance and elevation: on horizontal terrain never fire less than 500 meters in front of our troops, place the guns at least 1,000 meters behind troops in such a way that the average trajectory passes at least 15 meters above them.
Favorable distances of fire: from 1,500 to 3,500 meters. Do not open a barrage beyond 3,000 meters.
Rate of fire: do not expend more than 500 rounds per gun without letting it to cool down. The rate of 50 shots per minute for a gun can be sustained several hours and be mixed together with bursts of 500 rounds a minute. Under these conditions, a machine-gun company produces a well-fed barrage on a 100-meter front, and one that remains effective on a 200-meter front (12 or 25 meters per gun).
Shift the fixed barrage by minimal bounds of 200 meters.
Do not attempt rolling barrages.
A muzzle which fires 14,000 rounds is unfit to fire indirectly.
Under these limits, an indirect machine-gun fire can be requested in both the defensive and the offensive, harassing fire, blocking fire, concentrations on objectives of particular importance, containment and barrages.
In principle, the orders of a machine-gun emplacement for indirect fire dictates that with the signal requesting an artillery barrage, a machine-gun executes its barrage as well.
The formation, moved around as needed during the attack can open a barrage during the halts against intermediary objectives, and during several hours before the normal objective are taken. The preceding techniques of indirect fire can also be found in the annex on the “tactical instruction on the use of machine-guns.