From SH1

Question 1

what is line of sight?

Answer 1

line of sight is an imaginary line drawn from the firer’s eye through the sights to the point of aim

Question 2

what is burst of fire?

Answer 2

a burst of fire is a number of successive rounds fired with the same elevation and point of aim when the trigger is held to the rear. ( the number of rounds in a burst can vary depending on the type of fire employed).

Question 3

what is trajectory

Answer 3

trajectory is the curved path a round takes during its flight. Air resistance and gravity affect the trajectory of a round.

Question 4

what is maximum ordinate?

Answer 4

the maximum ordinate is the highest point above a line of sight to which a projectile rises during its flight. the maximum ordinate occurs approximately 2/3 of the way along the trajectory of the projectile. as the range increases so does the height of the maximum ordinate.

Question 5

what is cone of fire?

Answer 5

cone of fire is the group of trajectories resulting from a burst of fire. As the burst of fire strikes a vertical target, the rounds will form a pattern, oval in shape, with the density of shots decreasing towards the edges.

Question 6

what is beaten zone?

Answer 6

the pattern formed when the cone of fire strikes the ground is termed the beaten zone. it is oval or cigar shaped and the density of rounds decreases towards the edges.

(because of dispersion only that part of the beaten zone in which 85% of the round fall is considered the effective beaten zone.)

Question 7

what is danger space?

Answer 7

danger space occurs between the muzzle of the machine gun and the point of first graze. the extent of dangerous space will depend on the following:

1. range
2. height of the weapon above the target
3. height of the target engaged
4. shape of the ground
5. flatness of the trajectory

Question 8

what is dead space?

Answer 8

any fold or depression in the ground that prevents a target from being engaged from a fixed position is termed dead space.

Question 9

what are the factors that effect the burst of fire

Answer 9

when a burst is fired from a machine gun, no round follows the exact same path. the contributing factors that affect the flight of each round are:
1. The Gun
2. Ammunition
3 The Firer
4. Air disturbances
5. Clarity of Target

Question 10

how does ammunition affect the burst of fire?

Answer 10

Although modern day ammunition is very good, it does very slightly in metal composition and actual make up. the condition in which the ammunition is in when it is fired i.e.: wet, dirty, oily, etc, will influence the flight of a round.

Question 11

how does the firer affect the burst of fire?

Answer 11

the firer is influenced by the vibration of the gun, and is unable to maintain the same sight picture and firing position.

Question 12

how does air disturbances affect the burst of fire

Answer 12

the round can pass through hot or cold air disturbances, which will vary the flight paths of the rounds. gusts of wind will also cause the round to travel on separate paths.

Question 13

how does clarity of target affect the burst of fire?

Answer 13

the firer’s sight picture will also differ if the target is obscured by smoke or dust. the differing sight picture when firing the gun will cause round to travel on varying paths

Question 14

what happens when range increases on the beaten zone?

Answer 14

as range increases, the beaten zone becomes shorter and wider, due to the increased angle of descent at long ranges. the following dimension of the beaten zones at various ranges:
500m (1m wide x 110m long)
1000m (2m wide x 75m long)
1500m (3m wide x 55m long)
2000m (4m wide x 50m long)\
knowledge of the dimensions of the beaten zones at any range will assist you in the sighting and employment of your machine guns, especially in defense.

Question 15

explain the effects of ground on the beaten zone

Answer 15

ground will have a marked effect of the length of the beaten zone. a cone of fire striking a steep hillside will cover a very small area of ground and produce a small beaten zone. the same cone of fire striking a gentler slope will produce a slightly larger beaten zone. on level ground the beaten zone will be still larger. the largest beaten zone will result where the fall of the ground conforms to the trajectory of the round.

Question 16

what are the two types of machine gun fire?

Answer 16

1. Grazing fire
2. Plunging fire

the two factors that affect the type of fire produced by a gun are range and ground

Question 17

what is grazing fire?

Answer 17

grazing fire is obtained when firing over level or uniformly sloping terrain, where the center of the cone of fire does not rise more than 1 meter above the ground. this is approximately out to 600 meters. the danger space, employing this type of fire, extends from the muzzle of the weapon out to where the last round in the beaten zone strikes the ground.

Question 18

what is plunging fire?

Answer 18

plunging fire is achieved when the danger space is practically confined to the beaten zone. it is obtained when firing at very long ranges, from high ground or into abruptly rising ground.

Question 19

what is essential to engagement of target?

Answer 19

to obtain the maximum effective fire on a group of target it is essential that the machine gun is sighted so that the majority of targets are within the beaten zone of the weapon. this situation makes us e of the maximum effectiveness of the shape of the beaten zone and is termed enfilade fire.

Question 20

what is frontal fire?

Answer 20

frontal fire is when the long axis of the b eaten zone is at a right angle to the front of the target

Question 21

what is flanking fire?

Answer 21

flanking fire is fire that is delivered directly against the flank of a target

Question 22

what is oblique fire?

Answer 22

oblique fire is when the long axis of the beaten zone is at an angle other than a right angle to the front of a target.

Question 23

what is enfilade fire?

Answer 23

enfilade fire is when the long axis of the beaten zone coincides with the long axis of the target. this type of fire is either frontal or flanking. it is the most desirable type of fire with respect to a target because it makes maximum use of the beaten zone.

Question 24

When employed on the tripod using the iron sights or go, the maximum effective range is out to _________

Answer 24

1100 meters (the burn out range for tracer)

Question 25

when machine guns are used in the indirect fire role, they can be fired from _______ position and can engage targets that are not visible to the firer.

Answer 25

defiliade (reverse slope)

Question 26

in the sustained fire role, what is traversing fire?

Answer 26

traversing fire is used when the gun is traversed from left or right to encompass the entire target in the beaten zone.

Question 27

in the sustained fire role, what is traversing fire?

Answer 27

traversing fire is used when the gun is traversed from left or right to encompass the entire target in the beaten zone

Question 28

in the sustained fire role what does the term multiple fires mean?

Answer 28

multiple fires are a combination of different types of

1. enfilade/grazing
2. enfilade/plunging
3. frontal/grazing
4. oblique/plungin

Question 29

in the sustained fire role, what does the term defilade position mean?

Answer 29

A defilade position is where a gun can deliver fire onto a target from a position that is unable to be seen by the enemy and below the line of sight of flat trajectory weapons.

Question 30

in the sustained fire role, what does the term direct fire mean?

Answer 30

Direct fire is delivered directly onto the target by means of the iron sight or MGO when the line of sight can be achieved

Question 31

in the sustained fire role, what does the term fixed lines mean?

Answer 31

fixed lines are where measures have been taken to set the elevation and direction of the gun, so that fire will fall on a pre-arranged target. (Note: This is used for one target when the beaten zone covers the entire target).

Question 32

in the sustained fire role, what does the term fixed limits mean?

Answer 32

Fixed limits are where measures have been taken to set the elevation through a predetermined arc. (Note: This is used when a target has width requiring directional changes but not elevation changes).

Question 33

in the sustained role, what does the term zero line mean?

Answer 33

The zero line is the original bearing the guns are laid on. It is, where possible the center of arc of fire.

Question 34

in the sustained role, what does the term zero line mean?

Answer 34

The zero line is the original bearing the guns are laid on. It is, where possible the center of arc of fire.

Question 35

in the sustained role, what does the term registration mean?

Answer 35

Registration is the recording (by fire or silent) of the bearing and elevation required to hit a target.

Question 36

in the sustained role, what does the term mutual support mean?

Answer 36

Mutual support is where two guns are placed in such a manner that an attacking force cannot attack either gun without being seriously interfered with by the other.

Question 37

what are some notes when zeroing the weapon?

Answer 37

• if the weapon is not correctly zeroed, it is ineffective
• both the gunner and assistant gunner must zero the weapon.
• the AG must keep a record of his zero corrections.
• The spare barrel must be zeroed, not just the main barrel.
• The weapon must be zeroed before any operation, after being repaired, when gunners change, and whenever the zero is in doubt.

Question 38

what are some notes to consider on tracer?

Answer 38

• tracer can be observed out to approximately 1100 meters
• tracer is excellent for observing fall of shot.
• tracer is excellent for target indication by day or night.
• if you can see where your rounds are goin, the enemy can see where they are coming from.
• tracer is best-used 1 and 4 mix.
• 100% tracer looks great at night, but it will quickly burn out a barrel.
• tracer rounds will easily cause fires in grass and vegetation.
• at night, unless tracer is required, change belts or remove it.