Machine Gun Employment Flashcards
Define Trajectory
The arching flight path of the round from the muzzle of the
weapon to the target.
Define Ordinate
Elevation of the flight path of the round above the line of
sight
Define Maximum Ordinate
The maximum elevation of that round above the line of sight
along its flight path. This distance is reached at 2/3 the
distance to the target.
Define Cone of Fire
Each round fired from a machine gun travels a different
path. Vibration, tolerances of the ammunition and weapon,
and shooter positions all play a role in these differences.
The pattern of these rounds is called the cone of fire
For an
M240B the cone of fire is always
2 mils wide
Define Beaten Zone
The beaten zone is defined as the elliptical pattern formed
by the impact of the rounds. Again, because the cone of
fire is always 2 mils wide, the beaten zone as well is two
mils wide out to the maximum effective range of the gun.
There are, however, differences in the length based on the
Uniform terrain and Rising terrain and Falling terrain
Uniform terrain is
At short ranges the beaten zone will be
longer because of the initial trajectory and narrow because
of the relatively short distance the bullet travels before it
strikes the ground. As range increases, the beaten zone
decreases in length because the bullets will be falling at a
steeper angle and increases in width as the rotation of the
bullet further affects dispersion.
Rising terrain is
Terrain rising in the path of the cone of fire
has the effect of abruptly stopping the rounds and creates a
small beaten zone which nearly duplicates the pattern of
the cone of fire on steeply rising terrain.
Falling terrain is
When the terrain falls away before the gun, the
beaten zone becomes longer and depending on the range, either
long and narrow or long and wide.
Machinegun in relation to the ground is
Dead Space
Danger Space
Plunging Fire
Grazing Fire
Dead Space is
Dead space occurs anytime the target (or
enemy) drops below the line of aim or line of sight. This is
largely a product of terrain. Streams, ravines, draws and
other features may cause dead space.
Danger Space is
When firing over terrain, any space up to
1.8 m above the deck (the height of an average man) is
considered danger space; that is, within the effects of the
rounds.
Plunging Fire is
Plunging fire is defined where the danger
space is confined to the beaten zone. Plunging fire is
obtained when firing from high ground to low ground or low
ground to high ground and when using long range fires; an
example of this when a gunner engages a target on a street
from the third deck. The effects of the rounds are limited to
the beaten zone where those rounds are hitting the deck.
Grazing Fire is
Defines fire where the center of the cone of
fire does not rise more than one meter off the deck. This is
the most effective type of fire we can employ, and we will
always seek a position where we can bring the greatest
amount of grazing fire upon the enemy.
Machinegun in Relation to the Target is
Flanking Fire
Fontal Fire
Oblique Fire
Enfilade Fire
Flanking Fire is
Fires delivered on the flank of a target,
when the target is oriented 90 or more degrees away from
the firing unit.
Fontal Fire is
Fire delivered on the front of a target, when
the target is oriented on the firing unit.
Oblique Fire is
Fire delivered on the oblique of a target,
when the target is oriented between 0 and 90 degrees to the
firing unit.
Enfilade Fire is
The long axis of the beaten zone coincides with or nearly coincides with the long axis of the target. This class of fire is either Frontal or Flanking and is the most desirable class of fire with respect to the target, because it maximizes the use of the beaten zone.
Machinegun in Respect to the Gun is
Fixed Traversing Searching Traversing and Searching Swinging Traverse Free Gun
Fixed is
Fire delivered on a point target. Little or no manipulation of the gun is required to obtain and maintain effect on target.
Traversing is
fire delivered against a wide target requiring changes in direction. The beaten zones of each successive burst should be adjacent to each other if not overlapping (may be produced from either a tripod or bipod).
Searching is
Fire delivered against a target in depth requiring changes in elevation. The beaten zones of each successive burst should be adjacent to each other if not overlapping (may be produced from either a tripod or bipod).
Traversing and Searching is
fire delivered against an oblique target requiring changes in both elevation and direction. The beaten zones of each successive burst should be adjacent to each other if not overlapping (may be produced from either a tripod or bipod).
Swinging Traverse is
Fire delivered against targets which require major changes in direction with little or no change in elevation. Fired at the cyclic rate of fire using the tripod. (The beaten zones of each successive burst need not be adjacent to each other.)
Free Gun is
Fire delivered against moving targets that require major changes in both direction and elevation. The beaten zones of each successive burst need not be adjacent to each other (can only be produced from a tripod or vehicle mount). The T&E is not used as the manipulation is done by the Gunner.
Eight Principles of Machine Gun Employment are
PICMDEEP Pairs Interlocking Fires Coordination of Fires Mutual Support Defilade Enfilade Economy Protection
Pairs is
We attempt to employ machine guns in pairs at all times. Guns employed in pairs should not be separated by intervening terrain. 35 meters is the optimal separation between the two weapons systems, terrain dictating. This allows us to duplicate fires to ensure continuous fire support even if one gun goes down. This also gives us “talking guns”, giving us constant fires on the target and uninterrupted fires during immediate action drills or if a gun goes down. A SAW can be integrated to the pairs if needed.
