The second method (b) is only used where at least four guns are available, and requires six guns to obtain the best results. The range is estimated as before, and then each gun uses an elevation differing by 25 yards from the next: thus, taking 1,400 yards again as an example of the estimated distance, No. 1 gun will use 1,300; No. 2, 1,325; No. 3, 1,350, and so on, No. 6 using 1,425 yards.
In this way the effective zone of No. 1 gun, which is 60 yards in depth, will just overlap the effective zone of No. 2 gun, and so on right up to No. 6 gun. Thus instead of one small zone of 60 yards of effective fire, we have six guns joining to make one big effective zone 185 yards deep.
Care must be taken not to use more than 25 yards between sights at ranges over 1,400 yards, otherwise there will be gaps between each effective zone, and the fire would be ineffective should the target happen to be at a spot between any two zones.
The methods of firing the gun are laid down in the official Handbook, but it may be added that in using “deliberate” fire the double button should be pressed irregularly so as to imitate rifle fire, and with a little practice a rate of 120 shots a minute can easily be attained.
This kind of fire, although it should seldom be used, will occasionally be serviceable in ranging for observation when it is desired to do away with the peculiar sound of the machine gun and thus not disclose its presence prematurely. In covering a retirement it may also be found useful to deceive the enemy into believing they are only opposed by riflemen, while reserving its full fire power until a good target presents itself at close range.
“Continuous” fire should be used in “gusts” or bursts of from 15 to 30 shots, a momentary pause being made to observe the effect, and, if necessary, to correct the aim. The great expenditure of ammunition caused by “continuous” fire renders its use only justified when the effect obtained is commensurate, and it should seldom be adopted until the circumstances justify it. But when a really good target is found at close range, the ammunition need no longer be considered until there is nothing left alive to fire at. Annihilation should always be the final aim of machine-gun fire.
TAKING UP A POSITION
Except under special circumstances, such as for covering fire or a demonstration, the battery will not move as such into position, but each section will be given its approximate place and move there independently, keeping touch, however, by signal or connecting files with the battery commander and acting in close co-operation with the other sections.
Positions are of two kinds, viz. (1) positions of observation, (2) positions of readiness.
The position of observation will usually precede the position of readiness, and the principal points are the concealment of the guns and detachments, the facilities for observing the enemy and for movement in any direction.