Section III. OPERATION UNDER USUAL CONDITIONS

TM 9-6920-361-13&P

Section III. OPERATION UNDER USUAL CONDITIONS

any other easy, logical method can be used.

2-11. General. This section contains training

Additionally, problems may be encountered when

procedures, and instructions for operation of the trainer

traversing self-propelled weapons.

During large

M31 and the associated inbore subcaliber devices under

deflection changes, the weapons should be traversed in

conditions of moderate temperature and humidity. For

unison to avoid the possibility of hitting adjacent weapons

operation under unusual conditions see Section IV

with gun tubes.

2-12. Training Procedures.

CAUTION

During firing, the bore should be

WARNING

cleaned with the bronze bore brush

During firing mission, personnel

after every 10 to 15 rounds to reduce

should wear safety glasses, suitable

the possibility of a muzzle burst.

ear protection devices, and stand to

the rear of the weapon barrel.

(6) There is considerable buildup of

cosmoline in the tube during firing, and if it is not

a. Firing Battery Procedures.

removed, there is a loss in range. Eventually the

(1) When the 14.5-mm trainer is mounted

cosmoline buildup will cause a muzzle burst.

in the primary weapon as a subcaliber device, the on-

(7) It is not necessary to remove the 14.5-

carriage fire control equipment and traversing and

mm tube from the adapter for cleaning. Remove the bolt

elevating mechanism will be used to lay the weapon for

and swab the bore from the breech end of the tube.

direction and elevation.

After firing has been completed and the adapter is

(2) During firing, the weapon can be

removed, both the howitzer's primary tube and the 14.5-

serviced by a four-man crew-chief of section, gunner,

mm tube must be cleaned as though both tubes were

assistant gunner, and number 1 cannoneer. The chief of

fired. The adapter bore is cleaned using the same

section, gunner, and assistant gunner will perform their

cleaning material as used for the 14.5-mm device.

duties as though the primary weapon is being fired,

(8) A muzzle burst is currently considered

except the breech is not opened and closed. Cannoneer

a malfunction. In the event of a muzzle burst, the officer

number 1 will load the piece.

in charge of firing should report the malfunction to local

(3) During the conduct of the fire mission,

ammunition authorities. Normally the ammunition lot will

realistic commands are announced to the section; e.g.,

not be suspended, however,

the details of the

FIRE MISSION, BATTERY ADJUST AT MY COMMAND,

malfunction should be reported through proper channels.

CHARGE 1, DEFLECTION 3270, QUADRANT 365,

BATTERY 2 ROUNDS IN EFFECT (NUMBER 3 ONE

Observer Procedures.

ROUND SHELL HE, LOT X, FUZE Q HAVE BEEN

DESIGNATED AS STANDARD). Each command will

(1) When the observer is provided a

require the section to respond in much the same manner

special map as previously discussed, normal observer

as though the primary weapon were being fired.

procedures (including the use of an OF fan) are used to

(4) When the 14.5-mm bursts are more

determine target locations. The OT factor determined by

than five meters apart, the observer will have difficulty in

the observer is based upon thousands of decimeters

spotting the center of the two bursts for range.

rather than thousands of meters. For example, an

Therefore, when positioning the weapons, the lateral

observer-target distance of 2, 800 decimeters (280

distance between tubes should be about one-tenth the

meters) would result in an OT factor of 3. The observer

normal emplacement lateral distance.

Special

corrects for deviation by multiplying the measured

corrections can be applied to fire for effect data if the

deviation by the OT factor and announcing his

weapons are more than the normal distance apart, but it

corrections to the nearest ten decimeters; i.e., RIGHT

is unrealistic to habitually apply special corrections during

60.

fire for effect. Minimum quadrant elevation should be

computed and reported as normal operations. Crest

(2) The observer uses the bracketing

clearance for the 14.5-mm trainer is five decimeters.

method of range adjustment.

Caution should be

Either the tabular or graphical solution is acceptable.

exercised in establishing the range bracket because the

observer in many cases will think his rounds are much

(5) When using the inbore version in a six-

closer to the target than they actually are. As an

gun battery mode with all of the weapons separated by

example, if the rounds are 30 meters (300 decimeters)

five meters or less, some special techniques must be

short of the target, the observer should announce ADD

used.

Aiming posts and/or collimators should be

400 in order to obtain a range bracket.

identified by section to preclude a mixup of aiming points

between sections. Numbers, section colors, lights, or

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