Mortars Final Flashcards
Gun setting for min range
1511 mil and 0 charge
Traverse capabilities for 60mm
250 mil total
Difference between direct lay and direct alignment
Lay- gunner sees target
Alignment- FO observes target near gun target line
Most important position selection criteria
Mission accomplishment
60mm range
Min
Max
Handheld
Min-70m
Max-3490
Handheld-1340
Position selection factors
Mission accomplishment Tactical situation Range Target area coverage survivability Overhead and mask clearance Surface conditions Comms Routes
Range criteria
Mortars should be positioned to cover 1/2 to 2/3 of MER
Traverse settings for the 120
136 mil from center
316 mil total with extension
5mil per turn
If FO can’t be with in 100m of fun, how close must he be to the left or right of the gun
100m left or right
What are the two ways a commander displaces guns
On order Predetermined event (phase line)
How many turns of traverse are allowed when boresigting
2 turns
3 main parts for mortar rounds
Fuze
Body
Tail fun with propulsion system assembly
Parallel formation definition
Mortars online, distance between mortars=burst diameter of HE round
Which end of the needle on M2 do you use to index azimuth
South seeking (black tip)
Burst radius for 120
75m
Difference between successive and alternative bounding
A- bounding element passes other element
S- bounding element gets online with other element
How do you determine total turns of traverse
60/81-10mil per turn
120-5mil per turn
Rules for traversing fire
Width of target Total turns of traverse #of rounds # of intervals #of turns per interval
M67 sight capabilities
Magnification
Field of view
Mag-4x
FOV-10 deg
What happens if water gets in the tube
Short rounds
Ranges for the 120
Min-200m
Max-7.2km
60 mm bipod designation
M170A1
Number of turns per interval
Total turns required divided by number of intervals
Elevation settings for 120
0710-1510
81mm 3 types of rounds
HE
Illum
Smoke (WP/RP)
How do you find the mounting azimuth
Round azimuth to nearest 50mil
How do you make adjustments in direct lay
Refer sight to bisect splash then traverse back to target and re-bubble up
60mm baseplates
M7A1-circular, conventional
M8-box
M8A1- newer circular, hand held capable
What must you do if the base plate is not settled for direct lay
Level the bubbles and prepare to fire, remove the sight, fire two rounds, and put the sight back on and re-level bubbles
Number of intervals
1 less interval than round
Should you always use the lowest charge possible for range
Yes, unless you are close to the limit in order to avoid large deflections
120 tripod designation
M191
120/81/60mm mortar sight
M67
Gun settings for max range
800 mil max charge
60mm cannon designation
M225
81 M177A1 bipod settings Elevation 1turn Traverse 1 turn
Elevation- 800-1511
1 turn- 10mil
Traverse- 100mils from center
1 turn- 7 mil
Deflections rules
Azimuth
Mil adjustment
A-RALS(right add, left subtract)
M-LARS
80mm bipod designation
M177A1
81mm ROF
Max-30rnds per min, 2 min
Sus.-15rpm, indefinitely
60 rate of fire
Max-30RPM for 4 min
Sus- 20RPM indefinitely
What are two reasons an entire platoon can displace
Little likelihood of enemy contact
Another element can provide adequate support
M2 compass characteristics
Angle of sight scale
Azimuth scale
Angle=1200-0-1200
Azimuth=0-6400
20mil increments
Numbered every 200
M8 baseplate traverse capability
1600mil
81 range
Min-83m
Max-5,608
If FO is more than 100 m away, what ratio must he use for mil corrections
OT/GT
120mm cannon designation
M298
Advantages for engagements with out FDC
Speed and less people/equipment required
81mm baseplate designation
M3A2
At what distance should the aiming stakes be emplaced
100 and 50m
Or as far away as makes sense and half the distance
Rule of thumb for range estimates
0-2000m = 200m error 2000+m = 600-800m error
Main difference between hasty/deliberate and emergency
Emergency isn’t planned. Usually happens while in route to planned position. Considered a “hip shot”
M734 fuze settings birst heights
Prox=13-3ft
Near surface= 3-0ft
Impact
Delay-1/2sec
How are the mils graded on a whiz wheel
Numbered every 100, increment every 10
120 baseplate designation
M9
What must you do on the compass after finding the declination angle
Index it onto the compass
Which aiming stake is in the middle
Far pole in the middle
How are deviation corrections sent from FO
In mils
60 mm elevation settings
Upper saddle
Lower saddle
Upper=800-100
1 turn = 10mil
Lower=1101-1511mils
1full turn= 15mil
3 types of position occupation
Deliberate
Hasty
Emergency
81mm mortar cannon designation
M253
How do you find declination angle
Clockwise rotation from grid north to magnetic north
Main difference between hasty and deliberate
Amount of Time for advanced party to prepare. Both are planned
Determine # of rounds
60/81- 1rnd per 30m or 4rnd per 100m
120- 1 rnd per 60m or 2rnds per 100m
What’s the initial deflection for direct lay?
3200