CHAPTER 6

COMBAT TECHNIQUES OF FIRE


     The technique of fire is the method of delivering and controlling

     effective fire. The automatic rifleman must be trained in the standard

     methods of applying fire. This chapter discusses combat techniques of

     fire, application of fire on the battlefield, and advanced marksmanship.

     (See Appendix E for tactical employment.)

Section I. INTRODUCTION

Before the automatic rifle can be employed to its full potential, the soldier must know and be trained on characteristics of fire, classes of fire, types of targets, and application of fire.

6-1. CHARACTERISTICS OF FIRE

Each automatic rifleman must know the effects of bullets when fired. Factors influencing the path and strike of rounds are not limited to applying the fundamentals. They include the velocity of the round, gravity, terrain, atmospheric conditions, and the innate differences between each round.

    a. Trajectory. The trajectory is the path of the bullet in flight (Figure 6-1). The automatic rifleman must know the M249 AR's trajectory to effectively fire the weapon throughout its full range. The path of the bullet is almost flat at ranges up to 300 meters; then it begins to curve, and the curve becomes greater as the range increases.

    b. Maximum Ordinate. This is the highest point the trajectory reaches between the muzzle of the weapon and the base of the target. It always occurs about two-thirds of the distance from the weapon to the target. The maximum ordinate increases as the range increases (Figure 6-1).

Figure 6-1. Trajectory and maximum ordinate.

    c. Cone of Fire. When several rounds are fired in a burst from an M249 AR, each round takes a slightly different trajectory. The pattern these rounds form on the way to the target is called a cone of fire (Figure 6-2). This is caused primarily by vibration of the weapon and variations in ammunition and atmospheric conditions.

    d. Beaten Zone. The beaten zone (Figure 6-2) is the elliptical pattern formed by the rounds striking the ground or the target. The size and shape of the beaten zone changes when the range to the target changes or when the weapon is fired on different types of terrain. On uniformly sloping or level terrain, the beaten zone is long and narrow. As the range to the target increases, the beaten zone becomes shorter and wider. When fire is delivered on terrain sloping down and away from the weapon, the beaten zone becomes longer. When fire is delivered on rising terrain, the beaten zone becomes shorter. The terrain has little effect on the width of the beaten zone.

Figure 6-2. Cone of fire and beaten zone.

    e. Danger Space. This is the space between the weapon and the target where the trajectory does not rise above 1.8 meters (the average height of a standing soldier). This includes the area of the beaten zone. When the M249 is fired on level or uniformly sloping terrain at a target less than 700 meters away, the trajectory will not rise above the average height of a standing soldier. When targets are engaged on level or uniformly sloping terrain at ranges greater than 700 meters, the trajectory will rise above the average height of a standing soldier. Therefore, not all the distance between the weapon and the target is danger space.

6-2. CLASSES OF FIRE

Automatic rifle fire is classified with respect to the ground, the target, and the weapon.

    a. Fire with respect to the ground (Figure 6-3) includes grazing and plunging fires.

Figure 6-3. Classes of fire with respect to the ground.

    b. Fire with respect to the target includes frontal, flanking, oblique, and enfilade fires.

Figure 6-4. Frontal fire and flanking fire.

Figure 6-5. Oblique fire and enfilade fire.

    c. Fire with respect to the weapon (Figure 6-6) includes fixed, traversing, searching, and traversing and searching fires.

Figure 6-6. Classes of fire with respect to the weapon.

Section II. APPLICATION OF FIRE

Application of fire consists of the methods the automatic rifleman uses to cover a target area. Training these methods of applying fire can be accomplished only after the soldiers have learned how to recognize the different types of targets they may find in combat, how to distribute and concentrate their fire, and how to maintain the proper rate of fire. Normally, the automatic rifleman will be exposed to two types of targets in the squad sector: enemy soldiers and supporting automatic weapons. These targets have priority and should be engaged immediately.

6-3. TYPES OF TARGETS

Targets presented to the automatic rifleman in combat will usually be enemy troops in various formations, which will require distribution and concentration of fire. Targets with width and depth must be thoroughly covered by fire.

    a. Point Targets. These require the use of a single aiming point. Examples of point targets are enemy soldiers, bunkers, weapons emplacements, and lightly armored vehicles. Fixed fire is delivered at point targets.

    b. Area Targets. These may have considerable width and depth and may require extensive traversing and searching fire. These include targets in which the exact location of the enemy is unknown. The following are varieties of area targets likely to be engaged.

Figure 6-7. Linear target.

Figure 6-8. Deep target.

Figure 6-9. Linear targets with depth.

6-4. DISTRIBUTION, CONCENTRATION, AND RATE OF FIRE

The size and nature of the target determine how the automatic rifleman applies his fire. He must manipulate the M249 AR to move the beaten zone throughout the target area. The rate of fire must be controlled to adequately cover the target but not waste ammunition or destroy the barrel.

    a. Distributed fire is delivered in width and depth such as at an enemy formation.

    b. Concentrated fire is delivered at a point target such as an automatic weapon or an enemy fighting position.

    c. The rates of fire that can be used with the M249 AR are sustained, rapid, and cyclic. These rates enable leaders to control and sustain fire and prevent the destruction of barrels. More than anything else, the size of the target and ammunition supply dictate the selection of the rate of fire.

6-5. TARGET ENGAGEMENT

The automatic rifleman engages targets throughout his sector on his own under the direct control of a leader. He must know how to effectively engage all types of targets either by himself or in conjunction with another automatic rifleman.

    a. Single Automatic Rifleman.

Figure 6-10. Engagement of point target.

Figure 6-11. Engagement of area target.

Figure 6-12. Engagement of hard-to-identify targets with a reference point within the target area.

Figure 6-13. Engagement of hard-to-identify targets with a reference point within the target area.

    b. Pair of Automatic Riflemen.

Figure 6-14. Engagement of area targets with a pair of automatic riflemen.

Figure 6-15. Engagement of linear targets with a pair of automatic riflemen.

Figure 6-16. Engagement of deep targets with a pair of automatic riflemen.

Figure 6-17. Engagement of linear target with depth with a pair of automatic riflemen.

6-6. TARGET ENGAGEMENT DURING LIMITED VISIBILITY

Automatic riflemen have problems detecting and identifying targets during limited visibility. The leader's ability to control the fires of his weapons is also reduced. Therefore, he may instruct the automatic riflemen to fire without command when targets present themselves.

    a. Automatic riflemen should engage targets only when they can identify the targets, unless ordered to do otherwise. For example, if one automatic rifleman detects a target and engages it, the other automatic riflemen observes the area fired upon and adds his fire only if he can identify the target or if ordered to fire.

    b. Tracer ammunition helps an automatic rifleman engage targets during limited visibility and should be used, if possible. If firing unaided, automatic riflemen must be trained to fire low at first and adjust upward. This overcomes the tendency to fire high.

    c. When two or more automatic riflemen are engaging linear targets, linear targets with depth, or deep targets, they do not engage these targets as they would when visibility is good. With limited visibility, the center and flanks of these targets may not be clearly defined; therefore, each automatic rifleman observes his tracers and covers what he believes to be the entire target.

Section III. PREDETERMINED FIRES

Predetermined fires organize the battlefield for the automatic riflemen. They allow the leader and automatic riflemen to select potential targets or target areas that will most likely be engaged or that have tactical significance. This includes dismounted enemy avenues of approach, likely positions for automatic weapons, and probable enemy assault positions. The automatic riflemen do this by using sectors of fire, final protective lines, or a principal direction of fire and selected target areas. This preparation maximizes the effectiveness of the automatic rifle during good as well as limited visibility. It enhances fire control by reducing the time required to identify targets, determine range, and manipulate the weapon on to the target. Abbreviated fire commands and previously recorded data enable the automatic rifleman to aim or adjust fire on the target quickly and accurately. Selected targets should be fired on in daylight whenever practical to confirm data. The range card identifies the targets and provides a record of firing data.

6-7. TERMINOLOGY

Several terms are associated with predetermined fire that every automatic rifleman needs to know.

    a. Sector of Fire. A sector of fire is an area to be covered by fire that is assigned to an individual, a weapon, or a unit. Automatic riflemen are normally assigned a primary and a secondary sector of fire.

    b. Final Protective Fire. An FPF is an immediately available prearranged barrier of fire to stop enemy movement across defensive lines or areas.

    c. Final Protective Line. An FPL is a predetermined line along which grazing fire is placed to stop an enemy assault. If an FPL is assigned, the M249 is sighted along it except when other targets are being engaged. An FPL becomes the M249's part of the unit's final protective fires. An FPL is fixed in direction and elevation; however, a small shift for search must be employed to prevent the enemy from crawling under the FPL and to compensate for irregularities in the terrain or the sinking of the bipod legs into soft soil during firing. Fire must be delivered during all conditions of visibility.

    d. Principal Direction of Fire. A PDF is a direction of fire assigned priority to cover an area that has good fields of fire or has a likely dismounted avenue of approach. It also provides mutual support to an adjacent unit. Weapons are sighted using the PDF if an FPL has not been assigned. If a PDF is assigned and other targets are not being engaged, weapons remain on the PDF. A PDF has the following characteristics.

    e. Grazing Fire. A good FPL covers the maximum area with grazing fire. Grazing fire can be obtained over various types of terrain out to a maximum of 600 meters. To obtain the maximum extent of grazing fire over level or uniformly sloping terrain, the automatic rifleman sets the rear sight at 600 meters. He then selects a point on the ground that he estimates to be 600 meters from the weapon, and he aims, fires, and adjusts on that point. To prevent enemy soldiers from crawling under grazing fire, he searches (downward) by lowering the muzzle of the weapon. To do this, the automatic rifleman separates his elbows.

    f. Dead Space. The extent of grazing fire and the extent of dead space may be determined in two ways. In the preferred method, the weapon is adjusted for elevation and direction. A member of the squad then walks along the FPL while the automatic rifleman aims through the sights. In places where the soldier's waist (midsection) falls below the automatic rifleman's point of aim, dead space exists. Arm-and-hand signals must be used to control the soldier who is walking and to obtain an accurate account of the dead space and its location. Another method is to observe the flight of tracer ammunition from a position behind and to the flank of the weapon.

    g. Fire Control. Predetermined targets, including the FPL or PDF, are engaged on order or by SOP. The signal for calling for these fires is normally stated in the defense order. Fires on predetermined targets may be controlled by arm-and-hand signals, voice commands, or pyrotechnic devices. Automatic riflemen fire the FPL or PDF at the sustained rate of fire unless the situation calls for a higher rate. When engaging other predetermined targets, the sustained rate of fire is also used unless a different rate is ordered.

    h. Primary Sector of Fire. The primary sector of fire is the area to be covered by an individual or unit.

    i. Secondary Sector of Fire. The secondary sector of fire is the same area covered by the same individual or unit after it has moved to a different location.

6-8. RANGE CARD

The standard range card (DA Form 5517-R) provides a record of firing data and aids defensive fire planning. (See FM 7-8 for a reproducible copy of this form.) Its use enhances fire control and rapid engagement of predetermined targets. It is also used in estimating ranges to other targets within the sector of fire. Each automatic rifleman makes two copies--one for his position and one for the squad leader. The squad leader uses his copy to prepare his sector sketch. The range card is prepared immediately upon occupation and is constantly revised. Each range card contains the following:

Figure 6-18. Automatic weapon symbol.

    a. Procedures. The M249 AR is placed in the bipod-supported mode in the position it will be fired. The machine gun symbol is sketched on the range card pointing toward the most dangerous target in the sector.

Figure 6-19. Final protective line.

Figure 6-20. Principal direction of fire.

    b. Field Expedient. When laying the M249 AR for predetermined targets, the automatic rifleman can use field expedients as a means of engaging targets when other sources are not available.

Figure 6-21. Notched-stake or tree-crotch technique of engaging predetermined targets.

Section IV. FIRE CONTROL

Fire control includes all actions of the leader and soldiers in planning, preparing, and applying fire on a target. The leader selects and designates targets. He also designates the midpoint and flanks or ends of a target, unless they are obvious to the automatic rifleman. It is the automatic rifleman's responsibility to open fire at the instant desired, and then to adjust fire, regulate the rate of fire, shift from one target to another, and cease fire. When firing, the automatic rifleman should continue to fire until the target is neutralized or until signaled to do otherwise by the leader.

6-9. METHODS OF FIRE CONTROL

The noise and confusion of battle may limit the use of some of these methods; therefore, the leader must select a method or combination of methods that will accomplish the mission.

    a. Oral. This can be an effective method of control, but sometimes the leader may be too far away from the automatic rifleman, or the noise of the battle may make it impossible for him to hear. The primary means of the oral fire control method is the issuance of a fire command.

    b. Arm-and-Hand Signals. This is an effective method when the automatic rifleman can see the leader. All automatic riflemen must know the standard arm-and-hand signals. The leader gets the automatic rifleman's attention and then points to the target. When the automatic rifleman returns the READY signal, the leader commands FIRE.

    c. Prearranged Signals. These are either visual or sound signals such as casualty-producing devices, pyrotechnics, whistle blasts, or tracers. These signals should be included in SOPs. If the leader wants to shift fire at a certain time, he gives a prearranged signal such as smoke or pyrotechnics. Upon seeing the signal, the automatic rifleman shifts his fire to a prearranged point.

    d. Personal Contact. In many situations, the leader must issue orders directly to individual soldiers. This method is used more than any other by small-unit leaders. The leader must use maximum cover and concealment to keep from disclosing the position or himself.

    e. Standing Operating Procedures. SOPs are actions to be executed without command that are developed during the training of the squads. Their use eliminates many commands and simplifies the leader's fire control. SOPs for certain actions and commands can be developed to make automatic riflemen more effective. Some examples follow.

    f. Range Cards. When using this method of fire control, the leader must ensure all range cards are current and accurate. Once this is done, the leader may designate certain targets for certain weapons with the use of limiting stakes or with fire commands. He should also designate no-fire zones or restricted fire areas to others. The key factor in this method of fire control is that automatic riflemen must be well disciplined and pay attention to detail.

6-10. FIRE COMMANDS

A fire command is given to deliver effective fire on a target quickly and without confusion. When the leader decides to engage a target that is not obvious to the squad, he must provide them with the information they need to effectively engage the target. He must alert the soldiers; give a target direction, description, and range; name the method of fire; and give the command to fire. There are initial fire commands and subsequent fire commands.

    a. Initial Fire Commands. Initial fire commands are given to adjust onto the target, change the rate of fire after a fire mission is in progress, interrupt fire, or terminate the alert.

    b. Elements. Fire commands for all direct-fire weapons follow a pattern that includes similar elements. There are six elements in the fire command for the M249 AR: alert, direction, description, range, method of fire, and command to open fire. The automatic riflemen repeat each element of fire command as it is given.

    c. Subsequent Fire Commands. These fire commands are used to make adjustments in direction and elevation, to change rates of fire after a fire mission is in progress, to interrupt fires, or to terminate the alert. If the automatic rifleman fails to properly engage a target, the leader must promptly correct him by announcing or signaling the desired changes. When these changes are given, the automatic rifleman makes the corrections and resumes firing without further command.

    d. Doubtful Elements and Corrections. When the automatic rifleman is in doubt about any element of the fire command, he replies "Say again range, target." The leader then announces "The command was," repeats the element in question, and continues with the fire command.

    e. Abbreviated Fire Commands. Fire commands need not be complete to be effective. In combat, the leader gives only the elements necessary to place fire on a target quickly and without confusion. During training, however, he should use all of the elements to get automatic riflemen in the habit of thinking and reacting properly when a target is to be engaged. After the automatic rifleman's initial training in fire commands, he should be taught to react to abbreviated fire commands, using one of the following methods.

Figure 6-22. Arm-and-hand signals.

Section V. RANGE DETERMINATION

During combat, ranges are seldom known. Poor visibility and damp ground often make adjustment of fire by observation difficult if not impossible. Therefore, correct range determination is extremely important for accurate effective fire. Range estimation and lateral distance measurement are two methods used to determine the range to the target.

6-11. RANGE ESTIMATION

Range estimation is determining the distance between two points. In most situations, one of these points is the automatic rifleman's own position; the other point may be a target or prominent terrain feature. THE AUTOMATIC RIFLEMAN MUST ACCURATELY DETERMINE RANGE TO SET THE SIGHTS AND EFFECTIVELY FIRE ON A TARGET WITH THE FIRST BURST.

    a. Not only does the accurate estimation of range affect marksmanship, but it is also required in the reporting of information and the adjustment of artillery and mortar fire (Table 6-1).

Table 6-1. Factors of range estimation.

    b. There are several methods of estimating range. They include measuring distance on a map, pacing the distance between two points, and using an optical range finder. However, the automatic rifleman does not usually have a map and rarely has access to an optical range finder. He can pace the distance between two points if the enemy is not within range. Firing rounds to determine the range is not desirable, since it may reveal the position to enemy. Most of the time, the automatic rifleman must use techniques that do not require equipment and can be used without exposing himself or revealing his position. There are two methods that meet these requirements: the appearance-of-objects and the 100-meter-unit-of-measure.

Figure 6-23. 100m to 500m unit-of-measure method.

Figure 6-24. 100m to 800m unit-of-measure method.

6-12. LATERAL DISTANCE MEASUREMENT

In ad dition to estimating range accurately, the automatic rifleman needs a quick method of measuring lateral distance (right or left) from a reference point to a target. He can use his fingers to measure the lateral distance between a reference point and a target. He extends his arm with the palm outward, lowers the fingers, and locks the elbow. Then, he closes one eye, raises the index finger, and sights along its edge, placing the edge of the finger along the flank of the target or reference point. The space remaining between the points should be filled by raising fingers until the space is covered. He states the measurement from the reference point to the target as being one or more fingers, depending upon how many fingers are raised to cover this distance.

Section VI. ADVANCED AUTOMATIC RIFLE MARKSMANSHIP

Once the automatic rifleman masters the four fundamentals of automatic rifle marksmanship in the prone position and fighting position, he needs practice in applying the fundamentals in alternate positions and at targets that will most likely replicate the battlefield.

6-13. FIELD FIRING EXERCISE

The field firing exercise for the automatic rifleman exposes him to different types of targets at various ranges to simulate combat conditions.

    a. Objectives. The objectives of this training are to reinforce the fundamentals and increase the effectiveness of the automatic rifleman by building his confidence. He must acquire targets quickly and deliver an accurate volume of fire.

    b. Organization. The unit is assembled in the bleachers, given the training objectives, a range briefing, and a safety briefing. Automatic riflemen are then organized into firing orders with a firer and a coach. (It is necessary to have concurrent training stations set up for those soldiers not actually on the firing line).

    c. Ammunition. This exercise requires 148 rounds of 5.56-mm linked ammunition (zero is included). The automatic rifleman is allotted two 3-round bursts per target.

    d. Firing Sequence. The sequence of firing will be conducted IAW Firing Table IV (Table 6-2).

Table 6-2. Firing Table IV.

6-14. ALTERNATE FIRING POSITIONS

All automatic riflemen must master the bipod-supported prone and fighting positions to be effective. But it is equally important that they know other positions. Each automatic rifleman must be trained to assume different positions quickly during various combat conditions. The situation ultimately determines the position. The automatic rifleman must establish his position so that he can effectively observe and engage the target yet minimize his exposure from enemy fire.

    a. Shoulder-Firing Position. This position is usually used to engage targets at ranges less than 100 meters when no other position can be assumed or the situation dictates its use (Figure 6-25). It is the least stable of all positions, because the M249 AR is an open-bolt weapon that can be fired only on automatic. It is most often used in the final stages of the assault. To assume this position, the automatic rifleman--

Figure 6-25. Shoulder firing position.

    b. Underarm Firing Position. This position is used almost exclusively when moving and in and around the objective during the assault (Figure 6-26). To assume this position, the automatic rifleman--

Figure 6-26. Underarm firing position.

    c. Hip Firing Position. This position is used when closing with the enemy, when a heavy volume of fire in the target area is required, and when rapid movement is not necessary (Figure 6-27). The only differences between this position and the underarm position are--

Figure 6-27. Hip firing position.

6-15. MOVEMENT, SPEED, AND ALIGNMENT

The automatic rifleman must keep up with the other soldiers of the assaulting element through individual movement techniques. To do this, he moves as rapidly as possible, consistent with his ability to fire accurately and maintain alignment.

6-16. RELOADING

The automatic rifleman must reload rapidly to avoid lulls in the firing. This can be achieved by practicing and by applying the following techniques.

    a. Before the assault, the automatic rifleman conducts prefire checks on the weapon. He inspects ammunition to ensure that it is clean and serviceable, and he checks the box for serviceability.

    b. During the assault, the automatic rifleman must continue moving forward and reload as rapidly as possible. The sling allows the automatic rifleman to reload using both hands.

6-17. ALTERNATE FIRING POSITION EXERCISES

The assault fire exercise challenges the automatic rifleman. It consists of point and area targets under a variety of conditions replicating the battlefield. These exercises, which involve fire and maneuver, must be carefully controlled for safety purposes.

    a. Objectives. This exercise gives the automatic rifleman practice on engaging targets as quickly as possible, using any of the alternate firing positions.

    b. Organization. The unit is assembled in the bleachers, given instructions, and briefed on training that will be conducted while they are on the range. After the briefing, they are organized into firing orders and moved to firing lanes. Lanes are conducted and used IAW local range policies.

    c. Ammunition. This exercise requires a total of 75 rounds of 5.56-mm linked ammunition. The automatic rifleman is allowed two 3-round bursts per exposure, and he is also required to conduct at least one rapid reload during the exercise. The commander has the option as to when the rapid reload may take place. Ammunition is configured into two belts of any size that requires the automatic rifleman to reload.

    d. Firing Sequence. The sequence of firing is conducted IAW Firing Table V (Table 6-3). The suggested sequence of firing is as follows.

Table 6-3. Firing Table V.