Special Use of Machine Guns... 9-4
Employing Tank-Mounted Machine Guns
COAX MACHINE GUN
The coax machine gun can effectively engage area or point targets out to 900 meters, its maximum effective range (tracer burnout). When using the coax, the TC or gunner should set the LRF RANGE switch based on the operational environment.
Figure 9-1. Sight Picture for Lasing on Troops Using Last Return Logic.
ENGAGEMENT TECHNIQUE FOR AREA TARGETS
Immediately after lasing, the gunner should dump lead by quickly releasing then reengaging the palm switches. This rationale is based on the slow ballistic characteristics of the 7.62-mm round that cause the ballistic computer to induce a large lead angle. With the sweeping firing pattern (back and forth) used in these engagements, lead makes it difficult to place effective fire on the target.
After having lased and dumped lead, the gunner brings the reticle up to the center of the target area and fires an initial burst. An initial burst is a continuous burst fired through the target area, designed to kill as many troops as possible before they hit the ground or find cover.
After an initial burst has been fired, if pockets of resistance remain visible, use the machine gun area engagement technique, but shift to a 20- to 30-round burst using the Z-pattern technique.
Figure 9-2. Z-Pattern Technique for Area Targets.
In the offense, continue to move when engaging targets in the normal mode. Movement of the turret and vehicle carries the burst through the target when a narrow frontal area target is presented (see Figure 9-3). Round dispersion will cover target width.
Notes. Due to the rapid decrease in range to the target during offensive coax engagements, it may be necessary to re-lase to the target during the engagement.
The gunner must not forget to dump lead after re-lasing.
If the TIS or GPS is inoperative, use the HEAT reticle in the GAS. The range must be doubled, due to the ballistic mismatch of HEAT ammunition and the 7.62mm coax round. (If the target is at 800 meters, use the 1,600-meter range line.) The gunner may need to make an immediate correction to get a killing burst into the target area.
ENGAGEMENT TECHNIQUE FOR POINT TARGETS
When engaging point targets with the coax machine gun, follow the same manipulative procedures as with main gun engagements.
In normal mode, point targets can be engaged with the coax while the tank is on the move. Stabilization allows the gunner to use the GPS or TIS to acquire, identify, and fire on targets effectively without stopping the tank.
If the LRF is inoperative, use the GPS with the coax, battlesight range previously indexed. (Recommended coax battlesight range is 500 meters, unless specified otherwise by unit SOP.) The minimum battlesight range the Abrams will accept for coax is 25 meters.
If the GPS or TIS is inoperative, use the HEAT reticle in the GAS. Due to the ballistic mismatch of HEAT ammunition and the 7.62-mm coax round, the range must be doubled. (If the target is at 800 meters, use the 1,600-meter range line.) Also, if lead is to be applied, use 7½ mils initially, and correct as necessary.
LOADER'S MACHINE GUN
The loader's M240 machine gun is used to engage targets designated by the TC. When using the M240 machine gun, the loader should
• Lay the weapon for deflection.
• Fire bursts of 20 to 30 rounds (4 to 6 tracers) to engage all targets except aircraft. Engage aircraft using a continuous burst.
• Use tracer impact to adjust rounds on target.
When the loader is directed to engage targets with the M240, both the TC and loader must remember
• The loader's main duty is to load the main gun.
• The loader's machine gun does not have any sights; therefore, it should be used only for area or aerial targets.
• The TC's weapon and loader's machine gun can be fired simultaneously; however, caution must be used to prevent injury to the loader or TC.
• To avoid damaging the CITV, thermal shrouds, the bore evacuator, or the muzzle reference system collimator, the loader's machine gun should be fired only at targets to the left of the main gun.
The loader's stand should be adjusted so the chest-hold technique can be used to steady the M240 while firing. The loader grasps the handles of the loader's M240 mount, holds them closely against his chest for steadiness and control, and fires the weapon.
The loader fires a burst of 20 to 30 rounds, adjusting tracer impact onto the target or target area. If the gunner or TC sees the tracers, he assists the loader in adjusting his fire. These adjustments are given as
"UP/DOWN/RIGHT/LEFT." To terminate a loader's machine gun engagement, the TC announces "CEASE FIRE," or "LOADERCEASE FIRE," after a multiple weapons system engagement. If the target is destroyed during a multiple weapons system engagement, the loader announces “LOADER COMPLETE.”
During road marches, the loader acts as an air guard with his machine gun and covers his sector of responsibility. When engaging targets, the TC and loader do not cross each other's fire (this could injure crew members and damage equipment).
TANK COMMANDER'S WEAPON
The M2 HB caliber .50 machine gun is mounted in the CWS on the M1 and M1A1 Abrams tanks. The M2 HB flex caliber .50 machine gun is mounted in the ICWS on the M1A2 Abrams tank. (The M240 7.62-mm machine gun can be mounted in the CWS and the ICWS). The M2 machine gun can engage area and point targets out to 1,800 meters, its maximum effective range. If the M240 7.62-mm machine gun is mounted, it should only be used out to 900 meters (tracer burnout). When using the commander's weapon
• Lay the weapon for deflection and estimate the range. If the situation permits, the TC should have the gunner lase to the target and announce range; then, the TC should place the appropriate range line on target (M1 and M1A1 only).
• Fire bursts of 10 to 15 rounds (2 to 3 tracers) for the M2 or 20 to 30 rounds (4 to 6 tracers) for the M240 to adjust on target.
• Use the short-halt technique to engage targets while on the move.
On identification of an appropriate caliber .50 target, the TC announces "CALIBER FIFTY" and, on the M1 and M1A1, lays the appropriate range line on the target center of mass. On hearing the TC announce
"CALIBER FIFTY," the loader positions himself in the loader's hatch (if not buttoned up), assumes the TC's responsibilities for primary target acquisition (ground and air), and will assist in adjusting the TC's machine gun fire. If the gunner is engaging targets with the main gun, the loader must remain inside the turret. In all other situations, the loader should be out of the hatch, helping to sense rounds and acquire targets.
If the gunner or loader can see the caliber .50 tracers, he assists the TC in adjusting fire. These adjustments are given as "UP/ DOWN/RIGHT/LEFT." On completion of the caliber .50 engagement, the TC announces
"TC COMPLETE."
Figure 9-4. M1 and M1A1 Caliber .50 Aiming Points.