Employment/M252A1 Flashcards
When do you swab the tube?
Every 10 rounds or upon completion of fire mission.
How much does the M253 81MM cannon weigh?
30.5lbs
How much does the M3A2 baseplate weigh?
23lbs
How much does the M67 Sight unit weigh?
2.9lbs
What is the elevation range of the M252A1 81MM cannon?
0800 mils to 1511 mils
How many mils per turn on the elevation and traversing handwheel?
10 mils
How many mils right or left of center on the M177A1 mortar mount?
100 mils
Minimum and maximum range for the M252A1 81MM cannon?
Minimum- 83m
Maximum- 5608m
What are the rates of fire for the M252A1 81MM cannon?
Sustained- 15rpm
Maximum- 30rpm for 2 min.
What is the nomenclature for the aiming stakes and lights?
M14 aiming sights
M65 aiming lights
What are the 3 employment techniques?
By Platoon, section, or squad
What are the 3 methods or Reconnaissance?
Map
Air
Ground
What are the firing position selection factors?
Mission accomplishment Tactical situation Target area coverage Range Routes Survivability Surface conditions Communications Overhead and mask clearance
When mortars are positioned then need to be able to cover what percentage of their range?
1/2 to 2/3
What are the 3 types of occupation?
Deliberate
Hasty
Emergency
The BC or CO controls the displacement of the mortar platoon in what two ways?
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
When is displacement by platoon used?
When there is little immediate likelihood of enemy contact or when artillery can provide adequate support during displacement.
What is a parallel formation?
It has the mortars on line. The distance between mortar positions is the bursting diameter of HE ammunition for the particular mortar employed.
What is the bursting diameter for the 81MM HE?
40m
What are the 3 displacement techniques?
Displacement by platoon, section, or squad.
What is the magnification and field of view for the M67 Sight unit?
4x
10 degrees
What is a M2 compass capable of reading?
Magnetic and grid direction as well as elevation and depression
How is the Angle of Site mechanism graduated on the M2 compass?
0-1200 in two directions. Graduated in 20 mil increments and numbered every 200 mils
What is the range of the azimuth scale?
0-6400 mils in 20 mil increments
What are the 3 types of rounds for the M252A1 81MM?
HE
ILLUM
Smoke with RP/WP
What color are HE, ILLUM, and Smoke rounds?
HE- OD Green
ILLUM- White with black writing
Smoke- Light green
What type of round is a M816 and what fuse does it use?
IR Illumination
M772 MTSQ
What type of round is a M819 and what fuse does it use?
Smoke, RP
M772 MTSQ
What type of round is a M821/821A1 and what fuse does it use?
HE
M734 Multi-option
What type of round is a M853 and what fuse does it use?
Illumination
M772 MTSQ
M768 Time
What type of round is a M879 and what fuse does it use?
FRTC- Full Range Training Cartridge
M751 PD
What type of round is a M880 and what fuse does it use?
SRTC- Short Range Training Cartridge
M775 PD (Practice)
What type of round is a M889/889A1 and what fuse does it use?
HE
M935 PD
This fuze is moving out of circulation
What is the purpose of the obdurating ring?
Expands upon ignition forming a seal between the round and tube
What are the 6 different types of fuze settings?
PD- Point Detonating
IMP- Impact
SQ- Super Quick
NSB- Near surface burst
PROX- Proximity
DLY- Delay
What two settings are available on the M935 fuze?
SQ or DLY
What settings are available on the M734 fuze?
PROX
NSB
SQ
DLY
How far off the ground does PROX detonate?
1-3m
When should the aiming circle be declinated?
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
