Mortar Exam Prep Flashcards
List the mortar firing formations:
Parallel Lazy W Diamond Triangle 6 mortar star
Bursting diameter for 60mm, 81mm, 120mm HE rounds:
30m
40m
70m
List the 3 occupation techinques
Hasty
Deliberate
Emergency
Describe the difference between hasty and deliberate occupation?
Time available to prepare mortar site
What is emergency occupation?
Call for fire received during tactical movement, no site prep
What are the techniques to displace mortar?
If enemy contact is unlikely and there is another unit to support, you can move all the guns at once.
If that criteria is not met, you must move guns by section or squad via alternate or successive bounding
How are bounding techniques determined?
Speed of situation, enemy contact, terrain
During recon, what is the ideal range criteria for emplacing mortar systems?
Cover 1/2 to 2/3 of the mortar’s range and be able to shoot beyond friendly forces
List and describe the 3 effects of Indirect Fire:
Suppression: Enemy cannot perform job/duties
Neutralize: 10% casualties
Destroyed: 30% casualties or more
What are the 3 methods of recon?
Map, Air, Ground
List the 9 characteristics of position selection and which is most important?
#1 - Mission Accomplishment Tactical Situation Range Target Area Coverage Survivability Overhead and mask clearance Surface conditions Commo Routes
How many mortars makeup a platoon, section, and squad?
Platoon: 4 or more,
Section: 2 or 3,
Squad: 1
Describe the NSB fuze
Arms in flight, sends out radio waves waiting for object to give splash back, then goes off 0-1m above surface
Describe the PRX fuze
Similar to NSB, but goes off 1-4m above surface and rains steel
Describe Delay fuze
Detonates .05 seconds before ground impact.
Describe Superquick fuze
Detonates upon contact with surface
Does the multioption fuze (M734) have safety wires/pins ?
Absolutely not
Is there a safety on the Point Detonating M935 fuze?
Yes
What does a mortar round consist of?
Fuze, Body, Tailfin Propulsion System
Which fuze works best for troops in the open?
Impact/Super Quick, Point Detonate, NSB
Which fuze works best for targets in the prone, in shallow fighting positions?
PRX
What is the nomenclature for the aiming posts and how many are provided?
M14 and M1A2. 4 provided, can be stacked up to 2 high.
What is the nomenclature for the aiming post lights?
M58, M59. 2 green, 1 orange
What is nomenclature of the 81mm mortar system?
M252A1
What is the sustained and rapid rates of fire for the 81mm mortar?
Sustained: 15rpm
Max: 30rpm/2min
What are the components of the M252A1 system?
M253 cannon
M177A1 bipod
M67 gun sight
M3A2 baseplate
What is the minimum and maximum range for the M252A1
Min: 83m
Max: 5608m
What is the magnification power and field of view of the M67 optic?
4x magnification
FOV: 10*
What is the elevation range on the M177A1 bipod?
0800mils max to 1511mils min
What is the total traversing on the M177A1 bipod?
200 mil total (100 left/100 right)
How many mils are in each turn for the M177A1 bipod?
10mils traverse, 10mil elevation
What are 3 types of mortar rounds and their corresponding colors?
HE (olive drab green)
Illum (White)
Phosphorous (Light green)
What type of round is the M816 cartridge and fuze?
IR Illum, M772 MTSQ
What type of round is the M819 cartridge and fuze?
Smoke (Phosphorous), M772 MTSQ
What type of round is the M821 cartridge and fuze?
HE, M734 Multioption
What type of round is the M889 and fuze?
HE, M935PD
What are the options on the M734 fuze?
Proximity burst (1-4m above surface)
Near surface burst (0-1m above surface)
Impact (Superquick)
Delay (0.05 seconds above surface)
How many mils are in the M2 compass and what are the increments?
0-6400 in 20mil increments?
What are the capabilities of the M2 compass?
Magnetic Azimuth, Grid Azimuth, Angle of Sight
How is the azimuth indicated?
South end or solid black end
What is the angle of sight elevation scale in mils?
0-1200mils
What is the declination constant?
Clockwise angle from grid to mangetic
How far out do you ideally set aiming stakes?
100m for far, 50m for near
What is the rhyme for the large deflection change?
HEY DIDDLE DIDDLE, FAR POLE IN THE MIDDLE
What is the nomenclature and components of the 60mm mortar?
M224A1 mortar system M225A1 cannon M170A1 bipod M7A1 baseplate M8A1 baseplate M8 hand held base plate
What are the mil ranges for upper and lower saddle ont he M225A1?
Upper saddle: 0800-1100 mils
Lower saddle: 1101- 1511 mils
What is the range for the M225A1 in hand held and conventional?
Hand held: 70m - 1340m
Conventional: 70m - 3490m
What is the rate of fire for the M224A1
Max: 30rnd/ 4 min
Sustained: 20rpm indefinitely
How many mils can you traverse with the M170A1 Bipod?
250mils
How many mils are in 1 turn for the upper and lower saddle?
Upper saddle: 10 mil
Lower saddle: 15 mil
What is the nomenclature for the boresight?
M115
What is the max charge you can have on hand held mode?
Charge 1
What deflection and elevation do you boresight on for the 60mm?
Deflection 3200, Elevation 0800
What deflection and elevation do you boresight on the 81mm?
Deflection 0000, Elevation 0800
What deflection and elevation do you lay in on?
Deflection 3200, Elevation 1100
What is the M2 Aiming Circle: Azimuth rotation Max elevation Max depression Magnification Field of view
6400mils 800mils 400mils 4x 10*
How many levels are on the M2?
Two tubular vials and one fish eye
Why do we declinate?
To determine the declination constant of instruments and to correct for local attractions, annual variations, and instrument errors
When do we declinate?
When aiming circle moved 25mi or more
After electrical storm or severe shock
Every 30 days
When initially received and when returned to maintenance
How do you choose a point for a declination station?
Two distant, well defined points with a grid azimuth
If the declination constant is smaller than your mounting azimuth, what must you do?
Add 6400 mils
What do you say to being the reciprocal lay?
Section, aiming point this intstrument
Aiming circle operator: Aiming point this instrument!
Gunner what do you do and say?
Refer sight to the aiming circle operator lens, announce “Aiming Point Identified”
ACO: Places the vertical line of M2 optic on glass lens communicates deflection to gunner.
Gunner what do you do and say?
Place deflection on gun sight and manipulate mortar, “Gun 1 ready for recheck”
Gunner what do you say when you are within 0 or 1 mil or the mortar?
“Gun 1, 0 or 1 mil mortar laid”
What are the initial range changes per given range:
0-1000m
1000-2000m
2000 and greater
100m correction
200m correction
400m correction
How do you bracket in the rounds before fire for effect?
One round over, one round under
What type of fire do you apply to targets in width?
Traversing fire
What type of fire do you apply to targets in depth?
Searching fire
Do you use aiming stakes in direct alignment or direct lay?
Direct alignment (FO calls corrections)
How many intervals are in a fire mission?
Number of rounds minus 1
How far does one 60/81mm round cover?
30m
Which direction does the deflection scale get larger?
Left
What are the 2 methods of engaging targets without FDC?
Direct Lay, Direct Alignment
What do you make your gun corrections relative to? (Line)
Gun target line
How do you calculate turns between intervals?
# of turns traverse / # of intervals (12 / 6 = 2)
How many mils of traverse are in one turn on the 120mm?
5 mils
Who operates the Aiming Circle?
FDC
What is the maximum and minimum range of the 120mm mortar?
7200m max
200m minimum
Rate of fire for 120mm
16rpm/ 1st min
4rpm indefinitely
