Employment/M252A1

Question 1

When do you swab the tube?

Answer 1

Every 10 rounds or upon completion of fire mission.

Question 2

How much does the M253 81MM cannon weigh?

Answer 2

30.5lbs

Question 3

How much does the M3A2 baseplate weigh?

Answer 3

23lbs

Question 4

How much does the M67 Sight unit weigh?

Answer 4

2.9lbs

Question 5

What is the elevation range of the M252A1 81MM cannon?

Answer 5

0800 mils to 1511 mils

Question 6

How many mils per turn on the elevation and traversing handwheel?

Answer 6

10 mils

Question 7

How many mils right or left of center on the M177A1 mortar mount?

Answer 7

100 mils

Question 8

Minimum and maximum range for the M252A1 81MM cannon?

Answer 8

Minimum- 83m

Maximum- 5608m

Question 9

What are the rates of fire for the M252A1 81MM cannon?

Answer 9

Sustained- 15rpm

Maximum- 30rpm for 2 min.

Question 10

What is the nomenclature for the aiming stakes and lights?

Answer 10

M14 aiming sights

M65 aiming lights

Question 11

What are the 3 employment techniques?

Answer 11

By Platoon, section, or squad

Question 12

What are the 3 methods or Reconnaissance?

Answer 12

Map
Air
Ground

Question 13

What are the firing position selection factors?

Answer 13

Mission accomplishment 
Tactical situation
Target area coverage 
Range
Routes
Survivability 
Surface conditions 
Communications
Overhead and mask clearance

Question 14

When mortars are positioned then need to be able to cover what percentage of their range?

Answer 14

1/2 to 2/3

Question 15

What are the 3 types of occupation?

Answer 15

Deliberate
Hasty
Emergency

Question 16

The BC or CO controls the displacement of the mortar platoon in what two ways?

Answer 16

He can direct the option to displace on order. Which is the most restrictive way.

He can direct the mortar platoon to displace whenever certain predetermined events occur

Question 17

When is displacement by platoon used?

Answer 17

When there is little immediate likelihood of enemy contact or when artillery can provide adequate support during displacement.

Question 18

What is a parallel formation?

Answer 18

It has the mortars on line. The distance between mortar positions is the bursting diameter of HE ammunition for the particular mortar employed.

Question 19

What is the bursting diameter for the 81MM HE?

Answer 19

40m

Question 20

What are the 3 displacement techniques?

Answer 20

Displacement by platoon, section, or squad.

Question 21

What is the magnification and field of view for the M67 Sight unit?

Answer 21

4x

10 degrees

Question 22

What is a M2 compass capable of reading?

Answer 22

Magnetic and grid direction as well as elevation and depression

Question 23

How is the Angle of Site mechanism graduated on the M2 compass?

Answer 23

0-1200 in two directions. Graduated in 20 mil increments and numbered every 200 mils

Question 24

What is the range of the azimuth scale?

Answer 24

0-6400 mils in 20 mil increments

Question 25

What are the 3 types of rounds for the M252A1 81MM?

Answer 25

HE ILLUM Smoke with RP/WP

Question 26

What color are HE, ILLUM, and Smoke rounds?

Answer 26

HE- OD Green ILLUM- White with black writing Smoke- Light green

Question 27

What type of round is a M816 and what fuse does it use?

Answer 27

IR Illumination M772 MTSQ

Question 28

What type of round is a M819 and what fuse does it use?

Answer 28

Smoke, RP M772 MTSQ

Question 29

What type of round is a M821/821A1 and what fuse does it use?

Answer 29

HE M734 Multi-option

Question 30

What type of round is a M853 and what fuse does it use?

Answer 30

Illumination M772 MTSQ M768 Time

Question 31

What type of round is a M879 and what fuse does it use?

Answer 31

FRTC- Full Range Training Cartridge M751 PD

Question 32

What type of round is a M880 and what fuse does it use?

Answer 32

SRTC- Short Range Training Cartridge M775 PD (Practice)

Question 33

What type of round is a M889/889A1 and what fuse does it use?

Answer 33

HE M935 PD This fuze is moving out of circulation

Question 34

What is the purpose of the obdurating ring?

Answer 34

Expands upon ignition forming a seal between the round and tube

Question 35

What are the 6 different types of fuze settings?

Answer 35

PD- Point Detonating IMP- Impact SQ- Super Quick NSB- Near surface burst PROX- Proximity DLY- Delay

Question 36

What two settings are available on the M935 fuze?

Answer 36

SQ or DLY

Question 37

What settings are available on the M734 fuze?

Answer 37

PROX NSB SQ DLY

Question 38

How far off the ground does PROX detonate?

Answer 38

1-3m

Question 39

When should the aiming circle be declinated?

Answer 39

When it is moved 25 miles or more from the area it was declinated After an electrical storm or after receiving a severe shock Every 30 days When it is initially received and when it is returned from support maintenance repair