Theory of Fire

Question 1

Theory of Fire

Answer 1

Links the relationship between the projectile in flight, the influence on the gun and the sighting system to achieve a target hit at any range.

Question 2

Principle of Elevation:

Answer 2

A projectile fired from a gun at an object in line with the axis of the bore (AOB) will not strike that object but will fall short because of the influence of gravity and air resistance on the projectile during its flight. To compensate for this, it is necessary to point the gun above the object to be hit.

Question 3

6 Primary Terms of The Principal of Elevation

Answer 3

-Horizontal Plane (HP)
-Axis of the Bore (AOB)
-Line of Sight (LOS)
-Angle of Sight (AOS)
-Tangent Elevation (TE)
-Quadrant Elevation (QE)

Question 4

Horizontal Plane (HP)

Answer 4

The horizontal plane (HP) is an imaginary line drawn through the gun trunnions, parallel to the earth’s surface, but ignoring the curvature of that surface. It is the start point determining the amount of elevation required.

Question 5

4 Secondary Terms of the Principle of Elevation

Answer 5

-Line of Departure (LOD)
-Jump Angle
-Angle of Projection (AOP)
-Angle of Departure (AOD)

Question 6

Axis of the Bore (AOB)

Answer 6

The AOB is an imaginary line passing through the center of the bore.

Question 7

Line of Sight (LOS)

Answer 7

The line of sight (LOS) is an imaginary line passing through the sight and the target.

Question 8

Angle of Sight (AOS)

Answer 8

The angle of sight (AOS) is the vertical angle formed between the LOS and HP. When the LOS is above the HP, the angle formed is positive and when the LOS is below the HP, the angle formed is negative. The AOS governs whether more of less elevation is applied to the gun in order to hit the target.

Question 9

Tangent Elevation (TE)

Answer 9

Tangent elevation (TE) is the vertical angle formed between the LOS and the AOB when the gun is laid. It can be equated with the initial range calculated to the target.

Question 10

Quadrant Elevation (QE)

Answer 10

Quadrant elevation (QE) is the angle formed between the AOB and the HP when the gun is laid. It is a combination of TE, plus or minus the AOS.

Question 11

Line of Departure (LOD)

Answer 11

The line the projectile takes the instant it leaves the muzzle. This is not necessarily in the exact line of the AOB, it can be above or below it. Depending on whether jump is positive or negative.

Question 12

Jump Angle

Answer 12

The vertical angle formed between the AOB and the LOD when the gun is fired. It is caused by gun movement upon firing. The angle will vary depending on the gun and type of ammunition being fired.

Question 13

Angle of Projection (AOP)

Answer 13

The vertical angle formed between the LOS and the LOD when the gun is fired. It is the combination of TE and Jump.

Question 14

Angle of Departure (AOD)

Answer 14

The angle formed between the HP and the LOD. It is a combination of QE and Jump.

Question 15

Factors Affecting Elevation

Answer 15

1. Range to Target
2. Elevation of the Target
3. Jump
4. Gravitational Bending (Droop)
5. Thermal Bending
6. Meteorological Influences
7. Muzzle Velocity
8. Other Factors

Question 16

5 Components of Jump

Answer 16

1. Muzzle Point Angle (MP)
2. Muzzle Crossing Velocity (CV)
3. Center of Gravity Jump at the Muzzle
4. Aerodynamic Jump (AJ)
5. Sabot Discard Jump (SABOT ROUNDS ONLY)

Question 17

WHAT IS Line

Answer 17

Ballistic Term for Azimuth

Question 18

5 Factors that Affect Line

Answer 18

1. Ballistic Drift (FCS)
2. Throw-Off (ZERO)
3. Crosswind (FCS/MET)
4. Cant (FCS)
5. Thermal Bend (THERMAL SHROUD)