It is necessary, therefore, for its effective use, that its movements and fire action should be so regulated as to enable it to open fire rapidly whenever a favourable target presents itself, for the losses inflicted on an enemy will affect him in proportion to the suddenness and rapidity with which they are experienced. As the rôle of machine guns is to assist the particular body of troops to which they belong, the machine-gun commander should be fully acquainted with the orders issued to such troops. He should also carefully watch and conform to their movements, and assist them by every means in his power. As a rule the guns belonging to a unit will be employed singly in order to obviate the concentration of hostile fire against them, the most favourable position being sought for each weapon with regard to fire effect and cover; this, however, should not prevent the guns being used together when the circumstances of the moment demand the adoption of such a course. The massing of guns should be rarely resorted to. When it is desired to bring an overwhelming fire to bear on any locality, it should be accomplished by the concentration of fire from dispersed guns. The selection of a fire position should be preceded by careful reconnaissance on the part of the machine-gun commander. The following points should be looked for:
(a) A good field of fire.
(b) Concealment.
(c) Cover from the hostile fire.
(d) Possibilities for advancing to the position unobserved, and facilities for ammunition supply.
(e) Security against a covered hostile approach.
If a position affording concealment is not available, one should be selected which from the nature of its background will be difficult for the enemy to locate. As the opportunities for the effective action of machine guns will often be very brief, and as the guns will usually be employed singly, the non-commissioned officer in charge of each gun will, as a rule, have to act on his own initiative in choosing the objective, judging the range, and in deciding when to open fire. As a general rule, machine guns are best adapted for action at effective ranges; at these it is usually possible to distinguish the target, to ascertain its range, and to observe the effects of the fire. When, however, concealment and protection from fire exist, it may sometimes be advisable to bring machine guns into action at decisive range. If a sufficiently large target be offered and the range be known, the concentration and rapidity of their fire will enable guns to be employed, with considerable effect, at long ranges. Machine guns should seldom engage artillery at long rifle range, for in such circumstances superiority of fire will always rest with the latter if the machines are located. Within effective range, however, machine guns, if concealed, should inflict considerable loss on hostile artillery. Engagements with their lines of skirmishers should be avoided, for the risk of disclosing the position of the guns and the heavy expenditure of ammunition involved will rarely be justified by results. Since the gun is not well adapted for keeping up protracted fire, it may be often expedient to withdraw it from action, move it elsewhere, or hold it in reserve for a more favourable opportunity.
The selection of a target upon which to fire should be governed by (a) its tactical importance; (b) its dimensions and vulnerability. It is essential that due regard to economy of ammunition should be observed. When, however, it is decided to open fire, the ammunition necessary to secure the results sought must be expended without hesitation. “Deliberate fire” will rarely be resorted to. In cases where a favourable target is offered, prolonged “rapid fire” may be employed, but the most suitable description of fire will usually be “rapid” in series of from 25 to 30 rounds.
The range should be taken by a range-finder or ascertained from neighbouring infantry or artillery. Ranging by observation of fire should be employed only when the nature of the soil is very favourable and when no other method is practicable. When a reserve ammunition cart is provided for the machine guns it will be under the orders of the machine-gun commander, who will arrange that it is placed where it can most conveniently supply the guns with ammunition; it should be screened from view, and if possible sheltered from fire. All belts shall be refilled as soon as possible after they are emptied. Should the machine-gun commander consider an escort necessary, he will at once bring the fact to the notice of his commanding officer.
With Infantry in the Attack