Machine Guns

551. Machine guns are weapons of emergency. Machine guns must be considered as weapons of emergency. Their effectiveness combined with their mobility renders them of great value at critical, though infrequent, periods of an engagement. (537)

552. Machine guns to be used for short periods, when opportunities present themselves. When operating against infantry only, they can be used to a great extent throughout the combat as circumstances may indicate, but they are quickly rendered powerless by efficient field artillery and will promptly draw artillery fire whenever they open. Hence their use in engagements between large commands must be for short periods and at times when their great effectiveness will be most valuable. (538)

553. Machine guns attached to advance guard; use in meeting engagements. Machine guns should be attached to the advance guard. In meeting engagements they will be of great value in assisting their own advance, or in checking the advance of the enemy, and will have considerable time to operate before hostile artillery fire can silence them.

Care must be taken not to leave them too long in action. (539)

554. Use of machine guns with rear guard. They are valuable to a rear guard which seeks to check a vigorous pursuit or to gain time. (540)

555. Machine guns in attack; fire of position. In attack, if fire of position is practicable, they are of great value. In this case fire should not be opened by the machine guns until the attack is well advanced. At a critical period in the attack, such fire, if suddenly and unexpectedly opened, will greatly assist the advancing line. The fire must be as heavy as possible and must be continued until masked by friendly troops or until the hostile artillery finds the machine guns. (541)

556. Machine guns in defense. In the defense, machine guns should be used in the same general manner as described above for the attack. Concealment and patient waiting for critical moments and exceptional opportunities are the special characteristics of the machine-gun service in decisive actions. (542)

557. Machine guns as part of reserve; use in covering withdrawal. As part of the reserve, machine guns have special importance. If they are with the troops told off to protect the flanks, and if they are well placed, they will often produce decisive results against a hostile turning movement. They are especially qualified to cover a withdrawal or make a captured position secure. (543)

558. Machine guns not to form part of firing line of attack. Machine guns should not be assigned to the firing line of an attack. They should be so placed that fire directed upon them is not likely to fall upon the firing line. (544)

559. Effectiveness of machine guns against skirmish line, except when lying down or crawling. A skirmish line can not advance by walking or running when hostile machine guns have the correct range and are ready to fire. Machine-gun fire is not specially effective against troops lying on the ground or crawling. (545)

560. Silencing of machine guns by infantry. When opposed by machine guns without artillery to destroy them, infantry itself must silence them before it can advance.

An infantry command that must depend upon itself for protection against machine guns should concentrate a large number of rifles on each gun in turn and until it has silenced it. (546)

In addition to the above, which the Infantry Drill Regulations gives on the subject of machine guns, the following, based on the use of machine guns in the European War, is given:

561. Machine guns essentially automatic rifles. They are essentially automatic rifles, designed to fire the ordinary rifle cartridge and capable of delivering a stream of small bullets at a rate of as high as 600 per minute. Experience in the European war has determined that the rate of 400 shots per minute is the desirable maximum. Their ranges are the same as for the rifle. The fire of a machine gun has been estimated as equal to that of 30 men.

562. Mounts. Machine guns are usually mounted on tripods or wheels. The weight of certain types is such that they can readily be carried by the soldier from one point to another.

563. Methods of transportation. While machine guns are usually designed to be carried or packed, they are easily adapted to various methods of transportation. In the European war we find them mounted on sleds during the winter campaign; on specially designed motor cycles with side cars and accompanied by other motor cycles carrying ammunition; on wheels; on wagons; on armored automobiles; aeroplanes; and finally in the powerful "tanks" of the English.

564. Concealment. Machine guns while usually considered as weapons of emergency have been used in attack and defense in the European war in all stages. Their mobility and deadly effect have made them of great value. Once their position is discovered they are quickly put out of action by artillery. Owing to this fact the armies in Europe have used alternative positions and have used every means to conceal the guns. Hedges, walls, and pits are used and every effort is used to conceal the flame of discharge. This is usually accomplished by keeping the muzzle well in rear of its cover or loop hole. Machine guns almost invariably betray their positions as soon as they enter into action. The present tendency seems to be to hold them concealed and place them into position in the trenches or emplacements at the moment of combat.

Extraordinary means have been resorted to in hiding the guns until they are needed. In the German line, dugouts underground were constructed to conceal the machine guns and crews. Often they permitted the first line of the attack to pass over them and then appeared in rear and opened a deadly fire on the backs of the troops.

565. Use in villages. In villages, machine guns were used with terrible effect, firing from cellars or windows. The only successful method of destroying them was with hand grenades and even this was costly.

566. Location on the defense. On the defense machine guns should be mounted in salients and at points where cross fire can be obtained. This makes it more difficult for the enemy to locate the guns. Frontal fire is not so often successful.

567. Location in attack. In the attack it is accepted that machine guns must cover the Infantry at short and long ranges while other machine guns must accompany the attacking troops to hold the positions or trenches gained.

The second or third line would seem to be the best position for machine guns when accompanying troops.

568. Economy of men. Owing to its rapid and effective fire, and the comparative ease with which it can be concealed, the machine gun permits a great economy of men on a front and the concentrating of the forces thus freed for use in other parts of the field. This was done on a large scale on the Russian front by the Germans in 1915. They constructed miles of wire entanglements in front of positions occupied with an enormous number of machine guns and comparatively few men. The main forces were thus free to be transported wherever danger threatened. In this manner the Germans replaced men by machine guns and wire and were able to cope successfully with the immense Russian Armies. The above plate shows a typical machine gun emplacement, constructed in the field. Many elaborate emplacements have been constructed in the European war, using steel and concrete, but for a hasty cover in the field the simple emplacement shown in the figure is recommended.

(Note.—For a more detailed study of machine guns, see Subject XI, Machine Guns in Action, School of Musketry, Fort Sill, Oklahoma, and Combined Cavalry and Infantry Drill Regulations for Automatic Machine Rifle, cal. 30, 1909, War Department, 1915.)