(i) Surprise.—The early opening of fire discounts surprise, and, whether in attack or defence, often indicates the position of troops which would otherwise be unnoticed by the enemy. In attack it may delay the advance unnecessarily.
(ii) Effect of Fire at Different Ranges.—The effect of fire at various ranges must be taken carefully into account. This subject is dealt with in Sec. 43, para. 1.
5. Opening Fire in Attack.—(i) In connection with the considerations mentioned in para. 4 (i) and (ii) above, fire, as a general rule, should rarely be opened by infantry in attack when satisfactory progress can be made without it. The leading troops in particular should save every possible round for the final struggle for superiority of fire at close range, as the replenishment of ammunition in the firing-line at that time will be a matter of considerable difficulty.
(ii) When progress is no longer possible, fire should be opened, either by such parts of the firing-line as cannot advance, or by bodies of infantry specially detailed for this purpose, to enable a further advance to be made. Subject to these principles, fire may be opened in attack when there is a probability of its producing good effect, or when withholding fire might lead to heavy loss.
6. Opening Fire in Defence.—When infantry is acting on the defensive, there is usually less difficulty in arranging for the supply of ammunition. Fire may therefore be opened at longer ranges than when attacking, if it seems probable that any advantage will be gained thereby, especially when it is desired to prevent the enemy coming to close quarters, and when the ranges have been ascertained beforehand. If, however, the object is to gain decisive results, it is generally preferable to reserve fire for closer ranges and for surprise (Practice No. 1, p. 226).
7. Fire and Movement.—It is clear from the above considerations that fire is closely related to movement. The direct object of fire in the case of attack and counterattack is to facilitate movement, and also to check or hinder the movements of the enemy. The direct object of fire in defence is to check the movements of the enemy, and in the case of active defence to create an opportunity for the assumption of the offensive or for local counter-attacks. Fire, therefore, is related to movement, and its proper application with respect to movement is one of the principal objects of training in fire control.
Fig. 48 Diagram illustrating the Tactical Application of Fire.
8. Concentrated Fire ([Fig. 48]).—Collective fire may be concentrated or distributed. Concentrated fire produces a cone of fire favourable to observation of results, and is more effective than distributed fire at the point of application. Against narrow-fronted targets, such as the head of a column or a machine-gun, or against very vulnerable targets, or to produce an increased effect at a particular point, fire may be concentrated with advantage.
9. Distributed Fire.—(i) It is usually necessary to distribute fire so as to keep the enemy’s firing-line under fire throughout its length, in order to disturb his aim and prevent his movements. Fire employed to cover movements or directed on entrenchments should be distributed carefully and systematically [see also Sec. 54, para. 3 (v)].