071-000-0005 (SL1) - Prepare a Range Card for a Machine Gun

1.   Show the
gunner where to place fires on
designated targets during limited
visibility conditions such as night,
fog, or smoke.

2.   Provide the
gunner conducting a relief in place
with all the information he needs to
respond immediately to enemy action.

3.   Provide the
platoon leader and company commander
with information they need to plan
fires.

4.  
Write all necessary information
on the range card. Prepare a duplicate
range card for the platoon leader.
Include on both copies all sketches,
symbols (figure 071-000-0005-1)
and data.

Figure 071-000-0005-1.
Symbols.

a.
On the range card, roughly
sketch the terrain in front of the
position.

(1) 
Center the machine gun position
at the bottom of the sketch.

(2) 
Include any prominent natural
and man-made features that a target
could use to take cover.

b.
Using the lensatic compass,
determine magnetic north.

c.
Write the following
information in the top portion of the
range card (figures 071-000-0005-2
and 071-000-0005-3):

Figure 071-000-0005-2.
Primary sector with principal
direction of fire.

Figure 071-000-0005-3.
Primary sector with final protective
line.

(1) 
SQD. Write in the squad’s
designation.

(2) 
PLT. Write in the platoon’s
designation.

(3) 
CO. Write in the company’s
designation.

(4) 
MAGNETIC NORTH. Sketch the
direction for magnetic north using the
symbol shown in B, Figure 071-000-0005-1.

d.
Determine the location of the
gun position relative to a prominent
terrain feature. You could use a
hilltop, road junction, or
building–in other words, use either a
man-made or natural terrain feature.

(1) 
Use any terrain feature located
within 1,000 meters of the gun.

(2) 
If no such feature exists,
then, somewhere near the gun position
on the sketch, write in the
eight-digit map coordinates for your
position (figure 071-000-0005-2).

(3) 
Use a compass to determine the
azimuth in mils or degrees from the
terrain feature to the gun position or
from the gun position to the terrain
feature. Compute the back azimuth from
the gun to the feature by adding or
subtracting 3,200 mils or 180 degrees.

(4) 
Determine the distance between
the gun and the feature by pacing or
looking at a map.

(5) 
Draw the terrain feature in the
lower left- or right-hand corner of
the card, whichever better shows the
terrain feature’s position relative to
the gun.

(6) 
Draw a barbed line between the
position and the terrain feature.

(7) 
Above the line, record the
distance in meters.

(8) 
Below the line, record the
azimuth in mils or degrees from the
terrain feature to the gun.

(9) 
Use the direction of the
arrow’s barbs to show the direction of
the azimuth.

e.
Sketch in the primary sector of
fire (C, figure 071-000-0005-1),
using either a PDF or an FDL.

(1) 
FPL. Use a FPL (figure 071-000-0005-3
DATA SECTION, Item No. 1) only if the
position offers a good grazing
distance. Base the primary sector of
the line of fire. Make the FPL the
sector limit closest to friendly
troops.

(a)  
Sketch in the limits of the
primary sector of fire.

(b)  
Sketch in a FPL (D, figure 071-000-0005-1)
on the sector limit assigned by your
leader.

(c)  
Have someone walk the FPL (if
the enemy situation permits) to
identify and measure dead spaces (section[s]
of a FPL where a person drops below
the light of sight).

(d)  
Show the dead space(s) on the
sketch by a break(s) in the FPL
symbol. Write in the ranges to the
beginning and end of each dead space(s).

(e)  
Write in the maximum range
of graze.

(2) 
PDF. If you cannot identify an
FPL, you must assign a PDF (figure 071-000-0005-2 DATA
SECTION, Item No.1)

(a)  
Sketch in the limits of the
assigned primary sector of fire, whose
angle should not exceed 875 mils (the
maximum traverse of a tripod-mounted
machine gun).

(b)  
Sketch in the symbol for a
light automatic weapon (A, figure 071-000-0005-1).
Orient the symbol toward the most
dangerous target in the sector. Get
this information from the platoon
leader.

f. 
Label the targets in the
primary sector in their order of
priority. Label the FPL or PDF with
the number "1" (figures 071-000-0005-2
and 071-000-0005-3).

g.
Sketch in the secondary sector
of fire (E, figure 071-000-0005-1).

(1) 
Label the range (in meters)
from the gun to each target in the
secondary sector.

(2) 
Sketch in aiming and elevation
stakes between the gun position and
the target as shown in figures 071-000-0005-2
and 071-000-0005-3.

5.  
Using the T&E mechanism,
determine the direction, elevation,
and range to each target. Write this
information in the DATA SECTION of the
range card, as follows (figures 071-000-0005-2
and 071-000-0005-3):

a.
Center the traversing handwheel
on the center mark.

b.
If assigning an FPL, lay the
gun for direction. For this step, you
will not write anything on the range
card.

(1) 
Lock the traversing slide on
the extreme left or right side of the
bar, depending on which side of the
primary sector the FPL is on.

(2) 
Align the barrel on the FPL by
moving the tripod legs.

Figure 071-000-0005-4.
Traversing and elevating mechanism.

c.
When assigned a PDF, lay the
gun for direction.

(1) 
Align on the primary sector by
traversing the slide to one side.

(2) 
Move the tripod to align the
barrel on the sector limit.

(3) 
Align on the PDF by traversing
the slide until the machine gun is
aimed at the center of the target.

d.
Fix the tripod legs in place by
digging them in or sandbagging them.

e.
Determine the direction to each
target.

(1) 
Lay the gun on the base of the
target.

(2) 
Read the direction on the
traversing bar at the left edge of the
traversing bar slide (figure 071-000-0005-4).

(3) 
Determine by the direction of
the barrel whether the reading is
right or left.

f. 
Determine the elevation for
each target.

(1) 
Lay the gun on the base of
the target by rotating the elevating
handwheel (figure 071-000-0005-4).

(2) 
Read the number (including
a "+" or "-" sign,
unless the number is "0")
above the first visible line on the
elevating scale. (In figure 071-000-0005-4,
this reading is "-50.")

(3) 
Read, from the elevating
handwheel, the number in line with the
indicator. (In figure 071-000-0005-4,
this reading is "3.")

6.  
Record the data you found using
the T&E mechanism (figure 071-000-0005-4).

a.
Enter the reading in the
ELEVATION column in the DATA SECTION
of the range card, separating the two
numbers with a slash.

b.
Enter the range to each target
in the appropriate column in the DATA
SECTION.

c.
Enter the description of each
target in the appropriate column in
the DATA SECTION.

d.
Fill in the REMARKS block for
each target as needed.

e.
Enter the width and depth (in
mils) of linear targets. The
"-4" in figure 071-000-0005-3,
REMARKS block, means that depressing
the barrel 4 mils will cause the
strike of the rounds to go to ground
level along the FPL.

f. 
When entering the target width
(TW) in the REMARKS block, give the
width in mils, and express it in two
values. For example, in figure 071-000-0005-2, Target
3 measures 7 mils wide. The second
value, R3, means that if the gunner
lays the gun on the target and
traverses 3 mils to the right, the
point of aim will lay to the right
edge of the target. Target 3, figure 071-000-0005-3, shows
the width of the target as 15 mils;
traversing 8 mils to the left will
move the point of aim to the left edge
of the target.

g.
Do not determine data for the
secondary sector of fire; the gunner
will fire the weapon in the bipod
mode.

7.  
Keep one copy of the range card
at the machine gun position. Send the
other copy to platoon headquarters.
Complete range cards for primary
positions. Partially prepare range
cards for alternate and supplementary
positions. Prepare the range card as
soon as you arrive in a position,
regardless of the expected length of
stay. Continually revise the range
card the whole time you occupy the
position.

1.  
Prepared the range card.

—

—

a.
Sketched the terrain located in
front of the position.

b.
Determined the direction of
magnetic north.

c.
Sketched in the direction of
magnetic north.

d.
Completed the DATA SECTION.

e.
Determined the location of the
gun position relative to a prominent
terrain feature.

f. 
Sketched in the primary
sector of fire using either a PDF or a
FPL.

g.
Labeled the targets.

h.
Sketched in the secondary
sector of fire.

2.  
Used the T&E mechanism,
determined the direction, elevation,
and range.

—

—

a.
Centered the traversing
handwheel.

b.
Laid the gun for direction.

c.
Adjusted the tripod legs.

d.
Read the direction to each
target.

e.
Read the elevation to each
target.

3. Used
the T&E mechanism to determine
data for targets, then recorded it on
the range card.

—

—

a.
Entered the reading for
elevation into the ELEVATION block in
the DATA SECTION of the range card.

b.
Entered the range to the target
into the RANGE block in the DATA
SECTION of the range card.

c.
Described each target in
writings.

d.
Completed the REMARKS block for
each target, as needed.

FM
3-22.68