THE M240G MACHINEGUNNER. Maintenance Manual MCI 0321B (2007)

Lesson 1 Exercise

Directions

Complete exercise items 1 through 6 by performing the action required.

Check your answers against those listed at the end of this study unit.

Item 1

To lower the bipod for use, push in on the ________________________ to

release the bipod.

a. bipod latch

b. slide release latch

c. bipod lever

d. slide release lever

Items 2

Matching: For items 2 through 4, match the action for setting up the M122

Through 5

tripod in column 2 with the proper step in column 1 when using the tripod.

Column 1

Column 2

Order

Action

____ 2. Step 1

a. Attach the flex-mount.

____ 3. Step 2

b. Attach the M240G.

____ 4. Step 3

c. Set up the tripod.

____ 5. Step 4

d. Prepare the T&E.

Item 6

When preparing the T&E mechanism, you manipulate the elevation hand

wheel and the traversing slide until approximately _________ inches are

exposed on both the upper and lower elevation screws.

1/2

1 1/2

Continued on next page

MCI Course 0321B

3-17

Study Unit 3, Lesson 1 Exercise

Lesson 1 Exercise, Continued

Answers

The table below lists the answers to the exercise items on the previous pages.

If you have any questions about the items, refer to the reference page.

Item Number

Answer

Reference Page

3-4

3-7

3-9

3-11

3-14

3-9

Lesson

In this lesson, you have learned how to set up the M240G using the bipod,

Summary

tripod, and a tactical vehicle mount.

In the next lesson, you will learn how to properly load and unload

ammunition from the M240G.

MCI Course 0321B

3-18

Study Unit 3, Lesson 1 Exercise

LESSON 2

LOADING AND UNLOADING

Introduction

Scope

The M240G is designed to provide a heavy, controlled volume of accurate,

continuously, and long-range fire that is beyond the capabilities of individual

small arms to suppress and destroy the enemy. To keep M240G fire

continuous, the operator must be able to load the weapon correctly in a timely

manner.

In this lesson, you will learn the weapon condition codes as they apply to the

M240G and how to properly load and unload ammunition from the M240G.

Learning

Upon completion of this lesson, you should be able to

Objectives

• Identify the weapon conditions for the M240G.

• Identify the steps for loading the M240G with the cover open.

• Identify the steps for loading the M240G with the cover closed.

• Identify the steps for unloading the M240G.

In This Lesson This lesson contains the following topics:

Topic

See Page

Introduction

3-19

Weapon Conditions

3-20

3-21

Unloading

3-22

Lesson 2 Exercise

3-23

MCI Course 0321B

3-19

Study Unit 3, Lesson 2

Weapon Conditions

Four

The table below lists and describes the four weapon conditions for the

Conditions

M240G:

Condition

Description

The bolt is locked to the rear, the safety is engaged.

Ammunition is on the feed tray, the cover is closed.

Does not apply to the M240G.

The bolt is forward, the chamber is empty, and the safety is

disengaged. Ammunition is on the feed tray, the cover is

closed.

The bolt is forward, the safety is disengaged, and the feed tray

is clear of ammunition. The cover is closed.

MCI Course 0321B

3-20

Study Unit 3, Lesson 2

Cover Opened The steps for loading the M240G with the cover opened are listed in the table

below:

Step

Description

Clear the weapon (condition 4).

Open the cover.

Insert the link belt into the feed tray with the open side of the

link facing down.

Position the first round against the cartridge stop aligning it

with the feed tray grove.

Close the cover, ensuring it locks shut (condition 3).

Pull and hold the cocking handle to the rear, ensuring the bolt

locks to the rear.

Place the safety on SAFE (condition 1).

Return the cocking handle to the forward position.

Cover Closed

The steps for loading the M240G with the cover closed are listed in the table

below:

Step

Description

Ensure the cover is closed, the bolt is forward, and the safety is

on FIRE.

Insert the link belt into the feed tray with the open side of the

link facing down.

Push the first round into the feedway, ensuring the first round

engages the feed pawl and is held in place (condition 3).

Pull and hold the cocking handle to the rear, ensuring the bolt

locks to the rear.

Place the safety on SAFE (condition 1).

Return the cocking handle to the forward position.

MCI Course 0321B

3-21

Study Unit 3, Lesson 2

Unloading

Procedure

The procedure for unloading the M240G is listed in the table below:

Step

Description

Pull the cocking handle to the rear, ensuring the bolt locks to

the rear. Return the cocking handle to the forward position.

Place the safety on SAFE (condition 1).

Open the cover.

Remove the belt of ammunition and any links from the feed

tray.

Raise the feed tray and inspect the chamber and receiver for

rounds or brass.

Lower the feed tray. The weapon is now unloaded.

Note: After the weapon is unloaded, it can be reloaded to a condition 1

weapon or cleared to make a condition 4 weapon.

MCI Course 0321B

3-22

Study Unit 3, Lesson 2

Lesson 2 Exercise

Directions

Complete exercise items 1 through 4 by performing the action required.

Check your answers against those listed at the end of this lesson.

Item 1

Name and give a brief description of the four weapon conditions for the

M240G medium machinegun.

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

Item 2

List the steps in order to load the M240G with the cover open.

____________________________________________________________

Continued on next page

MCI Course 0321B

3-23

Study Unit 3, Lesson 2 Exercise

Lesson 2 Exercise, Continued

Item 3

List the steps in order when loading the M240G with the cover closed.

____________________________________________________________

Item 4

List the steps in order when unloading the M240G.

____________________________________________________________

Continued on next page

MCI Course 0321B

3-24

Study Unit 3, Lesson 2 Exercise

Lesson 2 Exercise, Continued

Answers

The table below lists the answers to the exercise items on the previous pages.

If you have any questions about the items, refer to the reference page.

Item Number

Answer

Reference Page

•

Condition 1. The bolt is locked to

3-20

the rear and the safety is engaged.

Ammunition is on the feed tray,

the cover is closed.

•

Condition 2 does not apply to the

M240G.

•

Condition 3. The bolt is forward,

the chamber is empty, and the

safety is disengaged. Ammunition

is on the feed tray, the cover is

closed.

•

Condition 4. The bolt is forward,

the safety is disengaged, and the

feed tray is clear of ammunition.

The cover is closed.

Clear the weapon (condition 4).

3-21

Open the cover.

Place the link belt in the feed tray

with the open side of the link

facing down.

Position the first round against the

cartridge stop aligning it with the

feed tray grove.

Close the cover, ensuring it locks

shut (condition 3).

Pull and hold the cocking handle

to the rear, ensuring the bolt locks

to the rear.

Place the safety on SAFE

(condition 1).

Return the cocking handle to the

forward position.

Continued on next page

MCI Course 0321B

3-25

Study Unit 3, Lesson 2 Exercise

Lesson 2 Exercise, Continued

Answers,

continued

Item Number

Answer

Reference Page

Ensure the cover is closed, the bolt

3-21

is forward, and the safety is on

FIRE.

Insert the link belt into the feed

tray with the open side of the link

facing down.

Push the first round into the

feedway, ensuring the first round

engages the feed pawl and is held

in place (condition 3).

Pull and hold the cocking handle

to the rear, ensuring the bolt locks

to the rear.

Place the safety on SAFE

(condition 1).

Return the cocking handle to the

forward position.

Pull the cocking handleto the rear,

3-22

ensuring the bolt locks to the rear.

Return the cocking handle to the

forward position.

Place the safety on SAFE

(condition 1).

Open the cover.

Remove the belt of ammunition

and any links from the feed tray.

Raise the feed tray and inspect the

chamber and receiver for rounds

or brass.

Lower the feed tray. The weapon

is now unloaded.

Lesson

In this lesson, you learned the weapon conditions as they apply to the M240G

Summary

and how to properly load and unload ammunition.

In the next lesson, you will learn how to fire the M240G.

MCI Course 0321B

3-26

Study Unit 3, Lesson 2 Exercise

LESSON 3

FIRING

Introduction

Scope

You are in your position. The M240G is mounted on the tripod with a full

belt of ammunition loaded. Now it is time to wait on the signal from the team

leader to begin engaging targets. What is next?

In this study unit, you will learn how to fire the M240G, including trigger

manipulation, sight adjustment and aiming, firing from the different mounts,

and changing the barrel.

Learning

Upon completion of this lesson, you should be able to

Objectives

• Identify trigger manipulation as it relates to rates of fire.

• Identify the use for the two position of the rear sight assembly.

• Identify the how to adjust the rear sight assembly.

• Define sight alignment.

• Define sight picture.

• Identify the guidelines when firing from the bipod.

• Identify the guidelines when firing from the tripod.

• Identify how to manipulate the traversing and elevating mechanism.

• Identify when to conduct a barrel change.

• Identify the steps for changing the barrel.

Continued on next page

MCI Course 0321B

3-27

Study Unit 3, Lesson 3

Trigger Manipulation

Trigger Control The trigger on the M240G is not squeezed as with other small arms. The

trigger is pulled to the rear to allow a burst of rounds to fire. This action

allows the gunner to control the number of rounds fired to achieve different

rates of fire. Bursts of six rounds or less should not be fired as this can cause

excessive wear on the sear and sear notch.

Rates of Fire

Achieving the different rates of fire with the M240G is accomplished by

holding down the trigger for a specific round burst. The rates of fire with the

associated firing information are listed in the table below:

Rate of Fire

Rounds per Minute

Burst

Pause

Rapid

200

10-12 rounds

2-3 seconds

Sustained

100

6-8 rounds

4-5 seconds

MCI Course 0321B

3-29

Study Unit 3, Lesson 3

Adjusting the Sights

The Front Sight The front sight can be adjusted using the front sight combination tool. This

adjustment is done during the zeroing procedure, which is covered in Lesson

4, “Adjusting the Front Sight Assembly.”

The Rear Sight The rear sight consists of a peep sight aperture on an adjustable sight leaf

slide. The sight leaf slide rides on a range plate with a graduated scale and is

attached to the receiver by a hinged plate. The rear sight has two positions—

horizontal and vertical.

Sight Position

Target Range

Used with

Horizontal

800 meters or less

Bipod or Tripod

Vertical

Greater than 800 meters

Tripod

Horizontal

In the horizontal position, the gunner can engage targets up to 800 meters.

Position

The sight is adjusted by squeezing the catches on the rear sight slide and

moving it forward or backward to the range setting on the range plate scale.

The range plate scale is marked in 100 meter increments from 200 to 800

meters. In this position, the peep sight aperture is used with the front sight

blade to aim at the target.

Continued on next page

MCI Course 0321B

3-30

Study Unit 3, Lesson 3

Adjusting the Sights, Continued

Vertical

In the vertical position, the gunner can engage targets from 800 meters to

Position

1,800 meters. The sight is adjusted by squeezing the catches on the rear sight

slide and moving it up or down to the required range setting on the range

plate scale. In the vertical position, the range plate scale is marked in 100

meter increments from 800 meters to 1800 meters. In this position, the

groove in the rear sight slide and the front sight blade are used to aim at the

target.

MCI Course 0321B

3-31

Study Unit 3, Lesson 3

Aiming

Sight

Sight alignment is the relationship between the front sight blade, the rear

Alignment

sight, and the aiming eye. When the rear sight is in the horizontal position,

obtain sight alignment by placing the tip of the front sight blade in the center

of the peep sight aperture. When the rear sight is in the vertical position,

obtain sight alignment by centering the front sight blade in the rear sight with

the tip of the front sight blade even with the bottom of the peep sight aperture.

Sight Picture

Sight picture is placing the tip of the front sight blade on the target while

maintaining sight alignment. Obtain a sight picture by centering the front

sight blade over the center of the target.

MCI Course 0321B

3-32

Study Unit 3, Lesson 3

Using the Bipod

Firing Position When firing the M240G while using the bipod, follow the guidelines listed

below:

• The gunner is in a prone position behind the weapon.

• The buttplate is placed into the right shoulder.

• The right hand grasps the pistol grip and manipulates the trigger.

• The left hand is placed on the comb of the stock, palm down.

• The cheek rests lightly on the buttstock and/or left hand.

• Exert a firm pressure with both hands to the rear during aiming and firing.

• Lean forward and apply forward pressure on the bipod.

Changing

The bipod attaches to the M240G with a ball joint allowing for minor changes

Direction

in direction up to about 45 degrees. To make a minor change in the direction

of fire, the gunner will shift the shoulders and upper torso to the left or right.

To make a major change in direction, the gunner’s entire body must move

until it is realigned behind the weapon.

Changing

To make changes in elevation, the gunner will simply move the elbows closer

Elevation

together or farther apart moving the stock of the weapon up or down.

MCI Course 0321B

3-33

Study Unit 3, Lesson 3

Using the Tripod

Firing Position When firing the M240G while using the tripod, follow the guidelines listed

below:

• The gunner is in a prone position behind the weapon.

• The right shoulder is placed against the buttplate.

• The right hand grasps the pistol grip and manipulates the trigger.

• The left hand is placed on the elevation hand wheel; palm down, to

manipulate the T&E mechanism.

• The cheek rests lightly on the buttstock.

• Exert a firm pressure with both hands to the rear during aiming and firing.

• Exert pressure down and to the right with the shoulder to take up the slack

in the T&E mechanism.

Orienting the

Before firing, the weapon should be adjusted so the muzzle is pointing in the

Weapon

general direction of fire. To do this, release the slide lock lever and move the

T&E mechanism to the left or right along the traversing bar. Once the

weapon is properly oriented, secure the slide lock lever.

Continued on next page

MCI Course 0321B

3-34

Study Unit 3, Lesson 3

Using the Tripod, Continued

T&E

All changes to the T&E mechanism will be made with the left hand. Changes

Manipulation

in direction (traversing) will always be made first then changes in elevation.

If the situation requires rapid changes in direction and elevation that cannot

be achieved with the T&E, the weapon should be fired from the bipod.

Changing

Changing the direction is called traversing. To traverse, place the left hand

Direction

on the traversing hand wheel, thumb up. To move the impact of the rounds to

the right, push (rotate) the traversing hand wheel away from you with the

thumb—push right. To move the impact of the rounds to the left, pull

(rotate) the traversing hand wheel to the rear toward you with the thumb—

pull left.

Continued on next page

MCI Course 0321B

3-35

Study Unit 3, Lesson 3

Using the Tripod, Continued

Changing

Changing the elevation is called searching. To search, rest the left hand on

Elevation

the elevation hand wheel. To increase the distance of the impact of the

rounds or up on a target, push (rotate) the hand wheel to the right with your

thumb—push up. To decrease the distance of the impact of the rounds or

down on a target, pull (rotate) the hand wheel to the left with your thumb—

pull down.

Using the

Estimate the range to the target and place the information on the rear sight.

Sights

Manipulate the T&E mechanism until there is a good sight picture on the

target. Once this is achieved, lower the rear sight if it is in the vertical

position. The tripod provides a stable base and control manipulation, which

makes the use of the sight during firing unnecessary. It will also block the

gunner’s view of the target and impacting rounds.

MCI Course 0321B

3-36

Study Unit 3, Lesson 3

Changing the Barrel

Overview

The ability to change barrels on the M240G is a great advantage. It allows

one barrel to cool while the other is being used. This increases the life of

each barrel and ensures a continuous rate of accurate fire. Changing the

barrels only takes a few seconds and significantly improves the rate of fire

and accuracy.

Frequency of

Barrels should be changed when they begin to overheat. Barrel change is

Changes

required after

•

10 minutes of firing at a sustained rate

•

2 minutes of firing at a rapid rate

Barrel

The barrel can be changed with the bolt to the front or to the rear. If the bolt

Changing

is to the rear, the weapon should be placed on SAFE. The procedure to

Procedure

change the barrel begins in the table below:

Step

Action

Depress and hold the barrel locking latch in.

Rotate the barrel carrying handle to the up position.

Note: Do not rotate the barrel carrying handle to the up

position using the carrying handle release latch. This

will not unlock the breach from the socket.

Continued on next page

MCI Course 0321B

3-37

Study Unit 3, Lesson 3

Changing the Barrel, Continued

Barrel

Changing

Procedure,

continued

Step

Action

Grab the spare barrel by the barrel changing handle.

Insert the barrel socket into the receiver ensuring the gas plug is

aligned with the gas cylinder.

Pull the barrel to the rear until the barrel is fully seated in the

receiver.

Continued on next page

MCI Course 0321B

3-39

Study Unit 3, Lesson 3

Lesson 3 Exercise

Directions

Complete exercise items 1 through 10 by performing the action required.

Check your answers against those listed at the end of this lesson.

Item 1

Complete the statement below.

Fire a burst of ______ rounds with a pause of _____ seconds to achieve a

rapid rate of fire.

Item 2

Complete the statement below.

In the down (horizontal) position, the rear sight allows for ranges from

_______ meters.

Item 3

Explain how to adjust the rear sight assembly to the required range setting.

_____________________________________________________________

Item 4

Define sight alignment.

_____________________________________________________________

Item 5

Define sight picture.

_____________________________________________________________

Continued on next page

MCI Course 0321B

3-41

Study Unit 3, Lesson 3 Exercise

Lesson 3 Exercise, Continued

Item 6

When firing the M240G from the bipod, the gunner is in a prone position

behind the weapon with the buttstock in the ________ shoulder with the

_______ hand on the pistol grip.

a. right; right

b. left; right

c. right; left

d. left; left

Item 7

When firing the M240G from the tripod, the gunner is in a prone position

behind the weapon with the _______ hand on the pistol grip and the _______

hand on the _________ hand wheel.

a. right; left; traversing

b. left; right; traversing

c. right; left; elevation

d. left; right; elevation

Item 8

Rotate the traversing hand wheel to the __________ to move the impact of

the rounds to the left.

Item 9

Change the barrel after firing for _______ minutes at the sustained rate.

Continued on next page

MCI Course 0321B

3-42

Study Unit 3, Lesson 3 Exercise

Lesson 3 Exercise, Continued

Item 10

List in order the steps to change the barrel on the M240G.

____________________________________________________________

Continued on next page

MCI Course 0321B

3-43

Study Unit 3, Lesson 3 Exercise

Lesson 3 Exercise, Continued

Answers

The table below lists the answers to the exercise items on the previous pages.

If you have any questions about the items, refer to the reference page.

Item Number

Answer

Reference Page

10-12; 2-3

3-29

200 to 800

3-30

Squeeze the catches on the side of the

3-30

rear sight and move it on the rear sight

slide to the desired range setting.

Sight alignment is the relationship

3-32

between the front sight blade, the rear

sight, and the aiming eye.

Sight picture is placing the tip of the

3-32

front sight blade on the target while

maintaining sight alignment.

3-33

3-34

rear toward you

3-35

3-37

Continued on next page

MCI Course 0321B

3-44

Study Unit 3, Lesson 3 Exercise

Lesson 3 Exercise, Continued

Answers,

continued

Item Number

Answer

Reference Page

Depress and hold the barrel locking

3-37 through

latch in.

3-40

Rotate the barrel changing handle to

the up position.

Push forward and up on the barrel

changing handle, separating the

barrel from the receiver.

Place the barrel on a clean surface

or the spare barrel bag to cool.

Grab the spare barrel by the barrel

changing handle.

Insert the barrel socket into the

receiver ensuring the gas plug is

aligned with the gas cylinder.

Pull the barrel to the rear until the

barrel is full seated in the receiver.

Rotate the barrel changing handle to

the down position, counting clicks

to verify proper headspace.

Lesson

In this lesson, you learned how to manipulate the trigger to achieve the

Summary

desired rate of fire, adjust the sights, aim, fire from the bipod and tripod, and

change the barrel.

In the next lesson, you will learn how to properly zero the weapon.

MCI Course 0321B

3-45

Study Unit 3, Lesson 3 Exercise

LESSON 4

ZEROING

Introduction

Scope

The ability to provide accurate long-range machinegun fire is the key to

successful support with the M240G. To help ensure that initial burst is on

target, the barrels on the M240G must be properly zeroed. If the initial burst

is not on target, you must adjust the impact of the rounds onto the target.

Spending time adjusting your position with the bipod or adjusting the T&E on

the tripod allows the enemy to respond to your attack.

In this lesson, you will learn the procedures for zeroing the barrels.

Learning

Upon completion of this lesson, you should be able to

Objectives

• Identify the steps for adjusting the elevation on the front sight assembly.

• Identify the steps for adjusting the windage on the front sight assembly.

• Identify the steps for conducting a battlesight zero of the M240G medium

machinegun.

• Identify the steps for conducting a field expedient zero of the M240G

medium machinegun.

In This Lesson This lesson contains the following topics:

Topic

See Page

Introduction

3-47

Adjusting the Front Sight Assembly

3-48

Battlesight Zero

3-51

Field Expedient Zero

3-52

Lesson 4 Exercise

3-54

MCI Course 0321B

3-47

Study Unit 3, Lesson 4

Adjusting the Front Sight Assembly

Adjusting Tool The front sight adjustment tool is part of the SL-3 components. It is used to

adjust the front sight of the M240G medium machinegun. It enables the

operator to unlock the front sight blade for adjusting elevation or turning the

socket head windage adjustment screws for adjusting windage.

Front Sight

There are two types of front sight blades. The number 1 blade is 9.8 mm and

Blade

the number 2 blade is 11.8 mm. If the required correction cannot be obtained

using the installed blade, the other blade should be used. The maximum

unscrewed position of either blade is where the base of the blade is flush with

the front sight protector surface. When zeroing, if the center of the shot group

is still above the point of aim with the number 1 blade unscrewed to the

maximum position, remove it and install the number 2 blade. If the center of

the shot group is still below the point of aim with the number 2 blade screwed

all the way in, remove it and install the number 1 blade. If the center of the

shot group cannot be brought to the point of aim after trying both blades, the

barrel assembly should be replaced.

Continued on next page

MCI Course 0321B

3-48

Study Unit 3, Lesson 4

Adjusting the Front Sight Assembly, Continued

Adjusting for

Rotating the front sight blade clockwise raises the point of impact on the

Elevation

target. Rotating the front sight blade counter-clockwise lowers the point of

impact on the target. To adjust for elevation, use the following procedures.

Step

Action

Using the combination front sight adjusting tool, unlock the

retaining strap and rotate it upwards.

Apply a few drops of lubricant to the base of the front sight

blade to make it easier to turn.

Using the slotted end of the tool, place it over the front sight

blade. Rotate the front sight blade in the desired direction for

the required number of turns.

Lower the retaining strap but do not lock it until the zero is

complete.

Continued on next page

MCI Course 0321B

3-49

Study Unit 3, Lesson 4

Adjusting the Front Sight Assembly, Continued

Adjusting for

Moving the front sight blade to the right moves the point of impact to the left.

Windage

Moving the front sight blade to the left moves the point of impact to the right.

The front sight windage adjustment procedure is the combination of creating

slack on one side, then taking up slack on the opposite side. The front sight

protector should always be tightly clamped between the two opposing

adjustment screws. As the adjusting crews are turned, noticeable clicks (eight

per full revolution) should be detected. If this is not the case, notify unit

maintenance. The procedure to adjust for windage is listed in the table below:

Step

Action

Using the hex wrench portion of the combination front sight

adjustment tool, loosen the adjusting screw on the side opposite

of the direction the front sight blade needs to move. To move

right, loosen left; to move left, loosen right.

Using the hex wrench, tighten the screw on the same side of the

direction the front sight blade needs to move. To move right,

tighten right; to move left, tighten left.

Once the windage is set, check that there is no play in the front

sight assembly. If there is, check both screws for looseness.

Note: The windage adjustment screws will break with the slightest over-

torquing. Be careful not to over tighten the adjustment screws.

MCI Course 0321B

3-50

Study Unit 3, Lesson 4

Battlesight Zero

Overview

Zeroing aligns the sights with the barrel so that point-of-aim equals point-of-

impact. Battlesight zero (BZO) is the sight settings used in combat and

enable engagement of targets within the M240G’s effective range in a no-

wind condition. The BZO is conducted with the M240G mounted on the

tripod at a range of 12.7 meters to the target. The target is a paper target with

a series of 1-inch black squares. Standard machinegun qualification targets

are normally used. When setting the BZO, all adjustments are made to the

front sight of the weapon. Each barrel of the M240G has to be individually

zeroed to ensure the accuracy of both barrels.

Procedure

The procedure for conducting a BZO is listed in the table below:

Step

Action

Leave the front sight post in its present position.

Set the rear sight elevation to 500 meters.

Load a belt of three rounds of ammunition.

Manipulate the T&E to get sight alignment and sight picture on

the 1-inch black square of the target.

Fire each round one at a time. Check the sight alignment and

sight picture between each shot.

Observe the impact of the group in relation to the target. Find

the approximate center of the group; this is the point of impact.

If the point of impact is not in the center of the target, adjust the

point of impact by manipulating the elevation and windage of

the front sight assembly based on the formula in the table below:

Adjustment

Formula

Elevation

1/2 turn equals 1/5 of an inch (5mm); 1 full

turn equals 3/8 of an inch (10mm).

Windage

1 full rotation (eight clicks) of the adjusting

screw equals 1/3 of an inch (8mm).

Repeat steps 3 through 7 to confirm the adjustments. If the

second shot group is not in the center of the target, continue

repeating until BZO is confirmed.

Repeat this procedure for the spare barrel.

MCI Course 0321B

3-51

Study Unit 3, Lesson 4

Field Expedient Zero

Overview

If the situation does not allow for the conduct of a BZO on a 12.7-meter firing

line, then a field expedient zero can be conducted. Any point of aim, point of

impact target can be used for a field expedient zero. A target that is between

300 and 700 meters is preferred. The target should be at the same elevation

as the firing position and have a solid mass behind it for observing the impact

of the rounds. For the field expedient zero, the M240G should be mounted on

the tripod.

Procedure

The procedure for conducting a field expedient zero is listed in the table

below:

Step

Action

Estimate the range to the target.

Place the range on the rear sight.

Center the T&E and adjust the position of the tripod to align the

gun to the target.

Adjust the T&E to get a correct sight alignment and sight

picture on the target.

Load a six-round belt of ammunition.

Fire a group of six rounds and observe the impact of the rounds

in relation to the target.

Continued on next page

MCI Course 0321B

3-52

Study Unit 3, Lesson 4

Field Expedient Zero, Continued

Procedure,

continued

Step

Action

If the center of the group does not impact the target, adjust the

elevation and windage of the front sight assembly.

•

To adjust the elevation, use the table below:

One full turn of the front sight blade

Range to Target

moves the impact of the round

100

4.25 inches

200

8.5 inches

300

12.75 inches

400

17.0 inches

500

21.25 inches

600

25.5 inches

700

29.75 inches

800

34.0 inches

900

38.25 inches

•

To adjust the windage, use the table below:

One full turn of the adjusting screws

Range to Target

moves the impact of the round

100

3.15 inches

200

6.3 inches

300

9.45 inches

400

12.6 inches

500

15.75 inches

600

18.9 inches

700

22 inches

800

25.2 inches

900

28.35 inches

Repeat steps 5 through 7 to confirm the zero.

Repeat for the spare barrel.

MCI Course 0321B

3-53

Study Unit 3, Lesson 4

Lesson 4 Exercise

Directions

Complete exercise items 1 through 4 by performing the action required.

Check your answers against those listed at the end of this lesson.

Item 1

List in order the steps for adjusting the elevation on the front sight assembly.

___________________________________________________________

Item 2

List in order the steps for adjusting the windage on the front sight assembly.

___________________________________________________________

Continued on next page

MCI Course 0321B

3-54

Study Unit 3, Lesson 4 Exercise

Lesson 4 Exercise, Continued

Item 3

Complete the following statement for adjusting the front sight assembly when

performing a battlesight zero on the M240G.

A half turn of the front sight blade moves the impact of the rounds _____

inches at 12.7 meters.

Item 4

Complete the following statement for adjusting the front sight assembly when

performing a field expedient zero on the M240G.

A full turn of the front sight blade moves the impact of the rounds ______

inches for every 100 meters of distance to the target.

Continued on next page

MCI Course 0321B

3-55

Study Unit 3, Lesson 4 Exercise

Lesson 4 Exercise, Continued

Answers

The table below lists the answers to the exercise items on the previous pages.

If you have any questions about the items, refer to the reference page.

Item

Reference

Answer

Number

Page

Using the combination front sight adjusting

3-49

tool, unlock the retaining strap and rotate it

upwards.

Apply a few drops of lubricant to the base

of the front sight blade to make it easier to

turn.

Using the slotted end of the tool, place it

over the front sight blade. Rotate the front

sight blade in the desired direction for the

required number of turns.

Lower the retaining strap but do not lock it

until the zero is complete.

Using the hex wrench portion of the

3-50

combination front sight adjustment tool,

loosen the adjusting screw on the side

opposite of the direction the front sight

blade needs to move. To move right,

loosen left; to move left; loosen right.

Using the hex wrench, tighten the screw on

the same side of the direction the front sight

blade needs to move. To move right,

tighten right; to move left, tighten left.

Once the windage is set, check that there is

no play in the front sight assembly. If there

is, check both screws for looseness.

1/5 (one fifth)

3-51

4.25

3-53

Lesson

In this lesson, you learned how to adjust the front sight assembly and zero the

Summary

M240G.

In the next lesson, you will learn how to troubleshoot the M240G if it fails to

operate properly.

MCI Course 0321B

3-56

Study Unit 3, Lesson 4 Exercise

LESSON 5

TROUBLESHOOTING

Introduction

Scope

In the middle of a firefight is not the time for your M240G to stop firing. If it

does, you must react quickly to identify and correct the problem and get the

weapon back into action. Your fellow Marines’ lives may depend on it.

In this lesson, you will learn how to identify a malfunction or a stoppage and

then apply immediate action or remedial action to remedy the problem.

Learning

Upon completion of this lesson, you should be able to

Objectives

• Define a malfunction.

• Identify sluggish operation.

• Identify the steps for adjusting the gas regulator setting.

• Identify a runaway gun.

• Identify the steps for correcting a runaway gun.

• Define a stoppage.

• Define a hangfire.

• Define a cook off.

• Define a hot barrel.

• Define immediate action.

• Identify the steps for applying immediate action.

• Define remedial action.

• Identify the steps for applying remedial action.

Continued on next page

MCI Course 0321B

3-57

Study Unit 3, Lesson 5

Malfunctions

Definition

A malfunction is a failure of the gun to function satisfactorily; the gun will

fire, but fire improperly. Defective ammunition or improper operation of the

gun by a crewmember is not considered a malfunction. Two of the more

common malfunctions are sluggish operation and a runaway gun.

Sluggish

Sluggish operation is when the M240G fires slower than its normal rate of

Operation

fire of 9 or 10 rounds per second. This can be due to excessive friction or a

loss of gas pressure. Excessive friction is due to a lack of lubrication or a

buildup of carbon or dirt in the gas system or on the bolt and receiver rails.

Loss of gas pressure is usually due to loose connections in the gas system.

The remedy for sluggish operation is for the operator to clean and lubricate

the weapon or have maintenance personnel tighten loose parts or replace worn

ones. If the current situation does not allow for this, sluggish operation can

be reduced by adjusting the gas regulator setting.

Gas Regulator The gas regulator plug has three different settings determined by three

Plug Settings

different size gas inlet holes. Each hole is numbered 1, 2, and 3. Hole 1 is

the smallest—the normal setting—and hole 3 is the largest. Always insert the

gas regulator plug with this setting after cleaning.

Continued on next page

MCI Course 0321B

3-59

Study Unit 3, Lesson 5

Malfunctions, Continued

Adjusting the

If the weapon becomes sluggish, the gas regulator plug can be removed,

Gas Regulator

rotated to setting 2 or 3, and reinserted. This adjustment should reduce the

Setting

sluggish operation until the operator can perform maintenance on the weapon.

The steps to adjust the gas regulator setting are listed in the table below:

Step

Action

Clear the weapon and make condition 4.

Remove the barrel.

Remove the gas collar and gas regulator plug.

Reinsert the gas regulator plug with setting 2 or 3.

Attach the gas collar.

Attach the barrel.

Continue with mission.

Runaway Gun

A runaway gun occurs when the weapon continues to fire after the trigger is

released. Firing is uncontrolled. A runaway gun is usually caused by a worn,

broken, or burred sear in the trigger housing group or a worn sear notch on

the operating rod. The sear shoulder is unable to grab the operating rod and

hold it to the rear after the trigger is released. The steps to stop a runaway

gun are listed in the table below:

Step

Action

Keep the weapon pointed towards the target.

If there are fewer than 50 rounds, let the rounds fire out.

If there are more than 50 rounds or the fire needs to cease

immediately, grasp the belt of ammunition with both hands and

twist the hands in opposite directions to break the belt of

ammunition.

Let the remaining rounds fire out.

Clear the weapon and make condition 4.

Turn weapon in to maintenance personnel for repairs before

using again.

Note: As a last resort, grasp the cocking handle and hold to the rear. This is

a last resort because of likely damage to the gun.

MCI Course 0321B

3-60

Study Unit 3, Lesson 5

Stoppages

Definition

A stoppage is any interruption in the cycle of functioning caused by faulty

action of the gun or defective ammunition that causes the weapon to stop

firing.

Hangfire

A hangfire occurs when there is a delay in the round firing after the firing pin

strikes the primer on the round.

Cook Off

A cook off occurs when a round discharges before being fully fed and locked

inside the chamber due to the high heat of the barrel.

Hot Barrel

A barrel is considered hot if more than 200 rounds have been fired in the last

2 minutes.

MCI Course 0321B

3-61

Study Unit 3, Lesson 5

Immediate Action

Definition

Immediate action is the prompt action taken by the operator to reduce a

stoppage without investigating the cause.

Procedure

When a stoppage occurs, you must react quickly to clear the stoppage and

return the weapon to operation in order to maintain a continuous rate of fire.

The procedure for conducting immediate action is illustrated in the chart

below:

Stoppage Occurs

Wait 5 seconds for possible

hangfire.

Attempt to

Let the barrel cool to air

lock the bolt to the rear.

temperature. Unload and

Can the bolt be locked

perform remedial action.

to the rear?

YES

Observe for

Attempt to fire. If the weapon fails

ejecting brass. Was a

to fire again, wait 5 seconds, lock

YES

round or casing

the bolt to the rear, unload, and

ejected?

perform remedial action.

Go to next page...

Continued on next page

MCI Course 0321B

3-62

Study Unit 3, Lesson 5

Remedial Action

Definition

When immediate action fails to correct the stoppage, remedial action must be

taken. Remedial action is the action taken to inspect, identify, and correct the

cause of the stoppage. The cause can be due to either the weapon or the

ammunition. Performing remedial action may involve some disassembly of

the weapon to determine the cause.

Procedure

The procedure for remedial action is based on the problem. To determine the

problem, use the cycle of operation as a guide to narrow down the cause.

Determine at what stage in the cycle of operation the weapon had a stoppage

and use the guidelines below.

Failure to Fire

If the weapon failed to fire on the initial burst, do the following:

on Initial Burst

• Check the safety. If the safety is on SAFE, place it on FIRE.

• Check the ammunition. Raise the cover and ensure the belt of ammunition

is loaded properly.

• Check the weapon condition. Pull the charging handle to the rear to

ensure the weapon is properly charged.

• Check the ammunition. Pull the charging handle to the rear to eject a

defective round.

Continued on next page

MCI Course 0321B

3-64

Study Unit 3, Lesson 5

Remedial Action, Continued

Failure to Feed If the weapon failed to feed ammunition properly, do the following:

• Make sure the rounds in the belt of ammunition are aligned properly.

Reload if necessary.

• Make sure the belt of ammunition is not inverted in the feed tray. If so,

remove it and load the ammunition with the open side of the links facing

down.

• Check the ammunition for defective links or rounds. Remove any

defective ammunition.

• Check for obstructions in the receiver. Remove any obstructions.

• Check the receiver and operating groups for proper lubrication. Apply

lubrication if needed.

• Check the cover assembly for damaged, missing, or weak parts. If

problems exist, notify unit maintenance.

• Make sure the cover is properly closed and secure.

Stops Firing

If the weapon stopped firing, do the following:

• Check for a defective round in the chamber and eject the round.

• Check for an unfired round with a dented primer. Eject the round and

notify unit maintenance.

• Check that the bolt assembly is fully forward and locked. Remove any

obstructions or clean and lubricate the operating group and inside the

receiver.

• Check for a sticking feeding mechanism. Clean and lubricate the feed

mechanism. If problem continues, notify unit maintenance.

• Check for a short recoil. Clean and lubricate the operating group and

inside the receiver. If problem continues, notify unit maintenance.

Sluggish

If the rate of fire cannot be maintained with proper trigger manipulation,

Operation

check for a dirty receiver. Clean and lubricate the receiver as necessary.

Continued on next page

MCI Course 0321B

3-65

Study Unit 3, Lesson 5

Remedial Action, Continued

Failure to

If the weapon failed to chamber a round, do the following:

Chamber

• Check for a stuck or ruptured cartridge case. Remove the stuck or

ruptured cartridge case.

• Check for dirty ammunition. Wipe the ammunition off with a clean rag.

• Check for built-up carbon in the receiver to include the gas cylinder.

Clean if necessary.

• Check for a damaged round. Remove the round and recharge the weapon.

• Check for a damaged or weak drive spring. Notify unit maintenance if

necessary.

• Check for a damaged gas regulator plug. Notify unit maintenance if

necessary.

• Check for a dirty chamber. Clean as necessary.

Failure to Fire

If the weapon failed to fire, do the following:

• Check for faulty ammunition. Unload and replace if necessary.

• Check for a damaged firing pin. Notify unit maintenance if necessary.

• Check for a damaged or weak drive spring. Notify unit maintenance if

necessary.

Failure to

If the bolt failed to extract a cartridge, do the following:

Extract

• Check for a short recoil. Clean and lubricate the operating group and

inside the receiver. If problem continues, notify unit maintenance.

• Check for a damaged extractor or extractor spring on the bolt. Notify unit

maintenance if necessary.

Continued on next page

MCI Course 0321B

3-66

Study Unit 3, Lesson 5

Remedial Action, Continued

Failure to Eject If the bolt failed to eject a cartridge, do the following:

• Check for a short recoil. Clean and lubricate the operating group and

inside the receiver. If problem continues, notify unit maintenance.

• Check for a damaged ejector or ejector spring on the bolt. Notify unit

maintenance if necessary.

• Check under the weapon to see if spent cartridges are piled high enough to

block ejection port. Clear away spent cartridges if needed.

Failure to Cock If the bolt failed to lock to the rear or cock the weapon, do the following:

• Check for a damaged or worn sear. Notify unit maintenance if necessary.

• Check for a stuck sear. Notify unit maintenance if necessary.

• Check for a damage or worn sear notch on the operating rod. Notify unit

maintenance if necessary.

• Check for a short recoil. Clean and lubricate the operating group and

inside the receiver. If problem continues, notify unit maintenance.

Continued on next page

MCI Course 0321B

3-67

Study Unit 3, Lesson 5

Remedial Action, Continued

Stuck

Over time, the extractor spring may weaken from use causing the extractor

Cartridge

not to tightly grip the base of the cartridge. When the bolt moves to the rear,

the cartridge is released and not removed from the chamber. Other times,

when a round is fired, some swelling of the cartridge occurs. When this

swelling is excessive, the cartridge can become fixed inside the chamber.

Removing a

The steps for removing a stuck cartridge are listed in the table below:

Stuck

Cartridge

Step

Action

Lock the bolt to the rear.

Place the weapon on safe.

Assemble the cleaning rod.

Insert the cleaning rod into the muzzle end of the barrel to push

the stuck cartridge out of the chamber.

Remove the cleaning rod.

Continue the mission.

Continued on next page

MCI Course 0321B

3-68

Study Unit 3, Lesson 5

Remedial Action, Continued

Ruptured

When a round is fired, it can cause the cartridge to weaken. Again, swelling

Cartridge

may occur. When both of these happen, the extractor may rip the base of the

cartridge off during the extraction process leaving behind the upper portion of

the cartridge in the chamber.

Removing a

The ruptured cartridge extractor tool is used to help the operator remove a

Ruptured

rupture cartridge. The steps for removing a ruptured cartridge are listed in the

Cartridge

table below:

Step

Action

Lock the bolt to the rear.

Place the weapon on safe.

Remove the barrel.

Insert the ruptured cartridge case extractor into the ruptured

cartridge.

Rotate the handle away from the barrel making the extractor

grasp the ruptured cartridge.

Holding the handle, pull the ruptured cartridge from the barrel.

Visually inspect the chamber for damage or debris. Clean if

necessary.

Reattach the barrel.

Continue the mission.

Continued on next page

MCI Course 0321B

3-69

Study Unit 3, Lesson 5

Remedial Action, Continued

Stuck and

When a ruptured cartridge occurs, there is a possibility that another round has

Ruptured

been chambered into the ruptured cartridge.

Cartridge

Removing

The steps for removing a stuck cartridge and a ruptured cartridge are listed in

Stuck and

the table below.

Ruptured

Cartridge

Step

Action

Lock the bolt to the rear.

Place the weapon on safe.

Remove the barrel.

Insert the cleaning rod into the muzzle end of the barrel to push

the cartridges out of the chamber.

Remove the cleaning rod.

If both cartridges have been removed, reattach the barrel and

continue the mission.

If the rupture cartridge remains, follow the procedure for

removing a ruptured cartridge.

Continue the mission.

MCI Course 0321B

3-70

Study Unit 3, Lesson 5

Lesson 5 Exercise

Directions

Complete exercise items 1 through 15 by performing the action required.

Check your answers against those listed at the end of this lesson.

Item 1

Define malfunction.

______________________________________________________________

Item 2

What is sluggish operation?

______________________________________________________________

Item 3

List the steps for adjusting the gas regulator setting.

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

Item 4

What is a runaway gun?

______________________________________________________________

Continued on next page

MCI Course 0321B

3-71

Study Unit 3, Lesson 5 Exercise

Lesson 5 Exercise, Continued

Item 5

List the steps for correcting a runaway gun.

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

•

____________________________________________________________

Item 6

Define stoppage.

______________________________________________________________

Item 7

Define hangfire.

______________________________________________________________

Item 8

Define cook off.

______________________________________________________________

Item 9

A barrel is considered hot if more than __________ rounds have been fired in

the last ______ minutes.

Continued on next page

MCI Course 0321B

3-72

Study Unit 3, Lesson 5 Exercise

Lesson 5 Exercise, Continued

Item 10

Complete the statement below.

Immediate action is the ___________________________________________

______________________________________________________________

Item 11

When applying immediate action to a weapon that has stopped firing, the first

thing the operator should do is

a. pull the charging handle to the rear.

b. remove the barrel.

c. wait 5 seconds in case there is a hangfire.

d. open the cover to investigate.

Items 12

Matching: For items 12 through 15, match the problem in column 1 with the

Through 15

likely cause in column 2.

Column 1

Column 2

Problem

Cause

___ 12. Stuck cartridge

a. Cover not completely closed

___ 13. Ruptured cartridge

b. Weak extractor spring

___ 14. Failure to feed

c. Damaged firing pin

___ 15. Failure to fire

d. Base ripped from cartridge

Continued on next page

MCI Course 0321B

3-73

Study Unit 3, Lesson 5 Exercise

Lesson 5 Exercise, Continued

Answers

The table below lists the answers to the exercise items on the previous pages.

If you have any questions about the items, refer to the reference page.

Item Number

Answer

Reference Page

A failure of the gun to function

3-59

satisfactorily; the gun will fire, but fire

improperly.

The M240G fires more slowly than its

3-59

normal rate of fire of 9 or 10 rounds per

second.

• Clear the weapon and make

3-60

condition 4.

• Remove the barrel.

• Remove the gas collar and gas

regulator plug.

• Reinsert the gas regulator plug with

setting 2 or 3.

• Attach the gas collar.

• Attach the barrel.

• Continue with mission.

The weapon continues to fire after the

3-60

trigger is released.

• Keep the weapon point towards the

3-60

target.

• If there are fewer than 50 rounds, let

the rounds fire out.

• If there are more than 50 rounds or

the fire needs to cease immediately,

grasp the belt of ammunition with

both hands and twist the hands in

opposite directions to break the belt

of ammunition.

• Let the remaining rounds fire out.

• Clear the weapon and make

condition 4.

• Turn weapon in to maintenance

personnel for repairs before using

again.

Continued on next page

MCI Course 0321B

3-74

Study Unit 3, Lesson 5 Exercise

Lesson 5 Exercise, Continued

Answers,

continued

Item Number

Answer

Reference Page

Any interruption in the cycle of

3-61

functioning caused by faulty action of

the gun or defective ammunition that

causes the weapon to stop firing.

When there is a delay in the round

3-61

firing after the firing pin strikes the

primer on the round.

When a round discharges before being

3-61

fully fed and locked inside the chamber

due to the high heat of the barrel.

200; 2

3-61

Immediate action is the prompt action

3-62

taken by the operator to reduce a

stoppage without investigating the

cause.

3-62

3-68

3-69

3-65

3-66

Lesson

In this lesson, you learned how to identify and respond to the various

Summary

malfunction and stoppages that may occur when operating the M240G.

Study Unit

In this study unit, you have learned how mount, load and unload, fire, zero,

Summary

and troubleshoot the M240G medium machinegun. You now have the

requisite knowledge to operate this weapon and use it in training and more

importantly, combat.

In the next study unit, you will learn how to engage targets in periods of

limited visibility and darkness using special optics.

MCI Course 0321B

3-75

Study Unit 3, Lesson 5 Exercise

STUDY UNIT 4

OPTICS

Overview

Scope

Your effectiveness as a machinegunner is based on your ability to engage

targets in periods of limited visibility and darkness. This can only be

accomplished through the use of optic systems designed for this purpose.

In this study unit, you will learn how to use special optics to engage targets

during periods of limited visibility and darkness.

In This Study

This study unit contains the following lessons:

Unit

Lesson

See Page

AN/PAS-13B V(2) Medium Weapon Thermal Sight

4-3

AN/PVS-17C Miniature Night Sight

4-17

MCI Course 0321B

4-1

Study Unit 4

LESSON 1

AN/PAS-13B V(2) MEDIUM WEAPON THERMAL SIGHT

Introduction

Scope

This lesson will acquaint you with the AN/PAS-13B medium weapon thermal

sight (MWTS)—its characteristics and reticle indicators. Basic operation and

the mounting and zeroing procedures will also be discussed.

Learning

After completing this lesson, you should be able to

Objectives

• Identify the fields of view on the AN/PAS-13B.

• Identify the four major components of the AN/PAS-13B.

• Identify the controls for the AN/PAS-13B.

• Identify the indicators for the AN/PAS-13B.

• Identify the parts of the M240 reticle.

• Identify the steps for mounting the AN/PAS-13B to the M240G.

• Identify the steps for installing the battery into the AN/PAS-13B.

• Identify the steps for operating the AN/PAS-13B.

In This Lesson This lesson contains the following topics:

Topic

Page

Introduction

4-3

General Information

4-4

Controls

4-5

Reticle

4-8

Mounting

4-11

Operation

4-12

Lesson 1 Exercise

4-14

MCI Course 0321B

4-3

Study Unit 4, Lesson 1

General Information

Description

The AN/PAS-13B V(2) MWTS is a silent, lightweight, compact, durable,

battery-powered thermal sight that operates with low power consumption.

The MWTS is capable of target acquisition under conditions of limited

visibility—such as darkness, smoke, fog, dust, and haze—and operates just as

effectively during daylight.

Characteristics The characteristics of the MWTS are listed in he table below:

Characteristic

Dimension/Description

Height

6.25 inches

Width

6.25 inches

Length

15.50 inches

Weight

4.19 pounds

Continued on next page

MCI Course 0321B

4-4

Study Unit 4, Lesson 1

General Information, Continued

Field of View

The MWTS consists of two fields of view (FOV)—narrow and wide:

FOV

Description

Magnification

Narrow

6º

5.0 ×

Wide

18º

1.66 ×

Four Major

The table below lists the MWTS components and their function:

Components

Component

Function

Telescope

Provides magnification of the thermal image

Sensor Assembly

Processes the thermal image for display

Eyepiece

Displays the thermal image and all system

indicators for the operator

Mount

Universal attachment that interface between the

MWTS and the weapon

MCI Course 0321B

4-5

Study Unit 4, Lesson 1

Controls and Indicators

Controls

The table below lists the MWTS controls and their function:

Item

Control

Function

Contrast Knob

Adjusts the contrast of the thermal scene.

When turned fully clockwise to the AUTO

detent position, contrast is automatically

controlled by the sight.

Emergency Select

Places the sight in emergency mode with the

system power on.

Brightness Knob

Turns system power ON and OFF. Adjusts

brightness of display.

Focus Knob

Adjusts focus of thermal scene.

FOV Knob

Selects either WIDE or NARROW field of

view.

Zoom/Reticle Select

Turns on the 2× zoom and changes the reticle.

Reticle Adjust

Used only for zeroing and sight aligning.

Black/White Select

Controls polarity (white hot or black hot) of

thermal scene.

Diopter Holding

For use with cathode ray tube display only. Not

Device

required on liquid crystal display. Allows

diopter to be adjusted.

Eyecup

Controls Standby or ON operating mode.

Diopter

Adjust focus of reticle and indicators.

Continued on next page

MCI Course 0321B

4-6

Study Unit 4, Lesson 1

Controls and Indicators, Continued

Indicators

The table below lists the MWTS indicators and their function:

Item

Indicator

Function

NOT COOL

Displays when the system is not cool enough for

proper operation

WHT HOT/BLK HOT

Indicates the target polarity selected by the

BLK/WHT switch

EMER

Displays when the system is placed in

emergency mode

LOW BAT

Displays when battery power is low.

Approximately 15 minutes of battery time

remain

Reticle select/FOV

Identifies which reticle and FOV is currently

selected

Elevation

Indicates the elevation zeroing adjustment of the

reticle

NFOV/WFOV

Indicates wide FOV or narrow FOV

RET ADJ

Indicates the reticle adjustment mode is selected

RET SEL

Indicates the reticle select mode is selected

Azimuth

Indicates the azimuth zeroing adjustment of the

reticle

SENSOR COOLING

Displays when system is first turned on and

switches to the current reticle after

approximately 2 minutes

Continued on next page

MCI Course 0321B

4-7

Study Unit 4, Lesson 1

Reticles

General

The M240 reticles provide multiple dot aim points and range gauges used for

range estimation and target firing. Each dot aim point is used for a different

range as indicated on the side of the range gauge. The bottom of the vertical

line above the 200-meter aim point is the 100-meter aim point. The height of

the vertical line at each aim point represents the height of a 5-foot tall man at

that range. The width of the horizontal line at each aim point represents the

width of a 10-foot-wide vehicle at that range.

Continued on next page

MCI Course 0321B

4-8

Study Unit 4, Lesson 1

Reticles, Continued

Zeroing Aim

The zeroing aim line is composed of the horizontal lines to the left and right

Line and

of the zeroing aim point. The zeroing aim line serves two purposes:

Zeroing Aim

Point

• Indicates the zeroing aim point for reticles with multiple aim points

• Provides a means of measuring angles for combat preparation, directing

fire, and range estimation

Zoom

The MWTS has a 2-times electric zoom. When the zoom is activated, the

image size is doubled and the FOV is cut in half as shown below:

MCI Course 0321B

4-10

Study Unit 4, Lesson 1

Mounting

Introduction

Make sure the M240G is in weapon condition 4 before mounting the

AN/PAS-13B. Avoid carrying the AN/PAS-13B by the eyecup, objective

lens cover, or battery cover. These items may detach from the site, causing it

to drop.

Procedure

The procedure for mounting the AN/PAS-13B to the M240G is listed in the

table below:

Step

Action

Make sure the rear sight of the M240G is in the down

(horizontal) position.

Loosen the mounting knob on the site.

Place the site on the mounting rail on the cover of the M240G.

Align the mounting rail of the AN/PAS-13 to the fourth slot

from the rear of the mounting rail on the M240G. Mounting the

site on a different slot can result in damage to the sight.

Hand tighten the mounting knob until two clicks are heard.

MCI Course 0321B

4-11

Study Unit 4, Lesson 1

Operation

Installing the

The procedure for installing the battery is listed in the table below:

Battery

Step

Action

Press in battery door latch, turn counterclockwise, and open

battery door.

Hold battery with contacts facing forward.

Install battery into battery compartment.

Close battery door. Press in while turning battery door latch

clockwise until battery door latch catches in slot. Continue

turning battery door latch one-quarter turn.

Continued on next page

MCI Course 0321B

4-12

Study Unit 4, Lesson 1

Operation, Continued

Operating the

The steps for operating the MWTS are listed below:

MWTS

Step

Action

Push in and turn the BRIGHTNESS knob fully clockwise to turn

to turn on power.

Place eye to eyecup and push to activate the display. During

initial cool down period, NOT COOL indicator is displayed and

reticle is replaced with SENSOR COOLING.

Adjust BRIGHTNESS knob for best display.

Adjust the diopter for best focus of the display.

Remove eye from eyecup to allow system to cool down.

Open objective lens cover on telescope.

Place eye to eyecup and push to activate display.

Set CONTRAST knob to AUTO or adjust for best scene.

Adjust FOCUS on telescope for best picture.

Adjust BRIGHTNESS knob for best picture.

Using BLK/WHT switch, select polarity as desired.

Rotate FOV ring to select WIDE or NARROW as desired.

Repeat steps 7 through 12 as needed to accomplish mission.

Following operation, push in and turn BRIGHTNESS knob fully

counterclockwise to the OFF detent position to turn off power.

MCI Course 0321B

4-13

Study Unit 4, Lesson 1

Lesson 1 Exercise

Direction

Complete exercise items 1 through 8 by performing the action required.

Check your answers against those listed at the end of this study unit.

Item 1

Complete the following statement.

What is the magnification for the narrow field of view (NFOV)?

______________________________________________________________

Item 2

List the four major components of the AN/PAS-13B.

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

Item 3

Which control knob is used to turn the system power on and off?

a. Contrast knob

b. Brightness knob

c. Focus knob

d. FOV knob

Item 4

What is displayed in the center of the reticle/display when you first turn on

the system?

a. SYSTEM COOLING

b. WHITE HOT

c. BLACK HOT

d. SENSOR COOLING

Continued on next page

MCI Course 0321B

4-14

Study Unit 4, Lesson 1 Exercise

Lesson 1 Exercise, Continued

Item 5

On the reticle, the zeroing line can be used for measuring angles in what unit

of measurement?

a. Meters

b. Feet

c. Degrees

d. Mils

Item 6

When mounting the AN/PAS-13B to the M240G, the mounting rail should be

aligned with the __________ slot from the rear of the mounting rail.

a. second

b. third

c. fourth

d. fifth

Item 7

To open the battery compartment door, push in and rotate the battery door

latch

a. clockwise.

b. counterclockwise.

c. upward.

d. downward.

Item 8

When operating the AN/PAS-13B, push in and turn the ______________

knob fully clockwise to turn on the power.

a. CONTRAST

b. POWER

c. BRIGHTNESS

d. FOCUS

Continued on next page

MCI Course 0321B

4-15

Study Unit 4, Lesson 1 Exercise

Lesson 1 Exercise, Continued

Answers

The table below lists the answers to the exercise items. If you have any

questions about these items, refer to the reference page.

Item Number

Answer

Reference Page

5.0 ×

4-5

• Telescope

4-5

• Sensor assembly

• Eyepiece

• Mount

4-6

4-7

4-8

4-11

4-12

4-13

Lesson

In this lesson, you were introduced to the AN/PAS-13B thermal weapon

Summary

sight. We covered characteristics, controls and indicators, mounting, and

operations.

In the next lesson, you will learn about the AN/PVS-17C miniature night

sight.

MCI Course 0321B

4-16

Study Unit 4, Lesson 1 Exercise

LESSON 2

AN/PVS-17C MINIATURE NIGHT SIGHT

Introduction

Scope

In this lesson, you will become familiarized with the AN/PVS-17C miniature

night sight. You will learn the characteristics and components of the sight.

You will be able to identify the control, how to mount the sight to the

M240G, and how to operate the sight.

Learning

After completing this lesson you should be able to

Objectives

• Identify the physical characteristics of the AN/PVS-17C.

• Identify the major components of the AN/PVS-17C.

• Identify the controls for the AN/PVS-17C.

• Identify the steps for installing a battery into the AN/PVS-17C.

• Identify the steps for mounting the AN/PVS-17C to the M240G.

• Identify the steps for operating the AN/PVS-17C.

In This Lesson This lesson contains the following topics:

Topic

See Page

Introduction

4-17

General Information

4-18

Controls

4-21

Mounting

4-22

Operation

4-25

Lesson 2 Exercise

4-26

MCI Course 0321B

4-17

Study Unit 4, Lesson 2

General Information

Description

The AN/PVS-17C miniature night sight (MNS) is a high performance,

compact, lightweight, monocular, night vision aiming system. The MNS

takes ambient/available light from night time sources—such as moonlight,

starlight, and sky glow—and amplifies it into a viewable image.

Physical

The MNS consists of the following physical characteristics:

Characteristics

Characteristic

Dimension/Description

Height

4.75 inches

Width

3.25 inches

Length w/eyeguard

11.375 inches

Weight w/battery

3 pounds

Operating

The MNS consists of the following operating characteristics:

Characteristics

Characteristic

Description

Operating Temperature Range

-40°F to +125.6°F (-40°C to +52°C)

Maximum Altitude

45,000 feet

Maximum Water Immersion (Fresh)

66 feet

Target Detection Range

500 meters

Magnification

4.5 times

Battery

1 AA alkaline or lithium battery

Continued on next page

MCI Course 0321B

4-18

Study Unit 4, Lesson 2

General Information, Continued

Major

The table below lists the MNS major components and their function:

Components

Item

Description

Function

Objective Lens

Provides magnification for imager

Image Intensifier

Amplifies available light into a

viewable image for the operator

Eyeguard

Provides protection for the eyepiece

optics, recoil protection for the

operator, and light security to within

10 meters

Eye Bumper (not shown)

Provides recoil protection for the

operator but no light security; used

instead of the eyeguard

Mount

Universal attachment that interface

between the MNS and the weapon

Daylight Filter

Protects the image intensifier from

bright light during limited daylight use

of the MNS for zeroing—a neutral

density

Continued on next page

MCI Course 0321B

4-19

Study Unit 4, Lesson 2

General Information, Continued

Internal Reticle The MNS contains an internal reticle that projects a red dot with an

intensified image of the viewed scene onto the eyepiece lens to provide an

aiming point for targeting. The illumination brightness of the red dot reticle

is controlled by the reticle brightness knob.

Low Battery

A yellow LED will illuminate in the eyepiece to indicate that a minimum of

Warning LED

30 minutes of battery life remains. It is located in the upper right of the

eyepiece.

MCI Course 0321B

4-20

Study Unit 4, Lesson 2

Controls

Description

The table below lists the MNS controls and their function:

Item

Control

Function

OFF-ON-ON

• OFF - Power is not provided to the

Selection Switch

image intensifier or reticle.

• ON - Used with the momentary button.

• ON - Continuous power to the image

intensifier and reticle.

Momentary

Power is applied to the image intensifier

Button

and reticle while this button is pressed and

held in.

Reticle

Consists of five levels of brightness to

Brightness Knob

adjust the brightness of the reticle.

Reticle Elevation

Used when zeroing the MNS

and Windage

Adjustment

MCI Course 0321B

4-21

Study Unit 4, Lesson 2

Mounting

Introduction

Make sure the M240G is in weapons condition 4 before mounting the MNS.

Avoid carrying the MNS by the eyeguard or objective lens cover. These

items may detach from the sight, causing it to drop.

Installing the

Before mounting the MNS to the M240G, you should install the battery. The

Battery

procedure for installing the battery is listed in the table below:

Step

Action

Make sure the objective lens cover is installed.

Place the OFF-ON-ON switch to the OFF position.

Open the battery compartment by rotating the battery cap

counterclockwise.

Insert the battery negative terminal first.

Place the battery cap on the battery compartment and rotate

clockwise until closed.

Continued on next page

MCI Course 0321B

4-22

Study Unit 4, Lesson 2

Mounting, Continued

Installing the

To mount the AN/PVS-17C to the M240G, the rail assembly mount must be

Rail Assembly

used. The procedure for mounting the rail assembly mount onto the

Mount

AN/PVS-17C is listed below:

Step

Action

Align the mounting screws on the rail assembly mount with the

threaded mounting holes on the bottom of the MNS.

Rotate the mounting screws clockwise using a flat tip

screwdriver until tight. Do not over-tighten.

Continued on next page

MCI Course 0321B

4-23

Study Unit 4, Lesson 2

Mounting, Continued

Mounting the

The procedure for mounting the AN/PVS-17C to the M240G is listed in the

MNS to the

table below:

M240G

Step

Action

Loosen the two knobs.

Slide the rail assembly mount onto the mounting rail.

Move the MNS forward until the recoil stops are aligned with

the recoil slots on the rail assembly mount.

Check the eye relief. Adjust the MNS on the mounting rail as

needed.

Tighten the rear knob and then the front knob. Repeat three

more times until knobs are tight.

MCI Course 0321B

4-24

Study Unit 4, Lesson 2

Operation

Precautions

When using the MNS during night operations, carefully read and understand

the following precautions:

• The equipment’s level of performance depends upon some night light—

moonlight, starlight, sky glow, etc.—to operate.

• Night light is reduced by passing cloud cover or while operating under

trees, in building shadows, etc.

• Equipment is less effective when viewing into shadows and darkened

areas.

• Equipment’s function degrades through rain, fog, sleet, snow, or smoke.

• Equipment’s function degrades underwater in cloudy, murky water

conditions.

• Make sure the objective lens cover is installed over the objective lens

when operating the MNS during the day.

Procedure

The steps for operating the MSN when mounted to the M240G are listed in

the table below:

Step

Action

Assume a firing position behind the weapon.

Place the OFF-ON-ON selection switch to the ON position.

Press your eye against the eye guard.

Rotate the BRIGHTNESS knob until the reticle is clearly visible.

Adjust the eyepiece focus ring until a sharp image of the reticle

is obtained.

Remove your eye from the eye guard.

MCI Course 0321B

4-25

Study Unit 4, Lesson 2

Lesson 2 Exercise

Directions

Complete exercise items 1 through 6 by performing the action required.

Check your answers against those listed at the end of this lesson.

Item 1

What is the magnification of the AN/PVS-17C MNS?

2.5 times

3.5 times

4.5 times

5.5 times

Item 2

List the six main parts of the AN/PVS-17C.

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

Item 3

To use the momentary button, the OFF-ON-ON selection switch must be in

the ___________________ position.

a. OFF

b. ON

c. OFF

d. ON

Continued on next page

MCI Course 0321B

4-26

Study Unit 4, Lesson 2 Exercise

Lesson 2 Exercise, Continued

Item 4

Before opening the battery compartment, you should ensure

____________________________________________________________

Item 5

To use the AN/PVS-17C with the M240G, the __________________ mount

must be used.

a. rail assembly

b. all purpose

c. night optic

d. receiver cover

Item 6

List the steps in order for operating the AN/PVS-17C mounted on an M240G.

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

•

___________________________________________________________

Continued on next page

MCI Course 0321B

4-27

Study Unit 4, Lesson 2 Exercise

Lesson 2 Exercise, Continued

Answers

The table below lists the answers to the exercise items. If you have you

questions about these items refer to the reference page.

Item Number

Answer

Reference Page

4-18

• Objective Lens

4-19

• Image Intensifier

• Eyeguard

• Eye Bumper

• Mount

• Daylight Filter

4-21

The objective lens cover is installed and

4-22

the OFF-ON-ON switch is in the OFF

position.

4-23

• Assume a firing position behind the

4-25

weapon.

• Place the OFF-ON-ON selection

switch to the ON position.

• Press your eye against the eye

guard.

• Rotate the BRIGHTNESS knob

until the reticle is clearly visible.

• Adjust the eyepiece focus ring until

a sharp image of the reticle is

obtained.

• Remove your eye from the eye

guard.

Lesson

In this lesson, you have learned the characteristics, components, and

Summary

operation of the AN/PVS-17C miniature night sight.

Study Unit

This study unit has familiarized you with two different optic systems for use

Summary

with the M240G, allowing you to operate in periods of limited visibility or

darkness.

MCI Course 0321B

4-28

Study Unit 4, Lesson 2 Exercise

M240G MEDIUM MACHINEGUNNER

REVIEW LESSON EXAMINATION

Review Lesson

Introduction

The purpose of the review lesson examination is to prepare you for your final

examination. We recommend that you try to complete your review lesson

examination without referring to the text, but for those items (questions) you

are unsure of, restudy the text. When you finish your review lesson and are

satisfied with your responses, check your responses against the answers

provided at the end of this review lesson examination

Directions

Select the ONE answer that BEST completes the statement or that answers

the item. For multiple choice items, circle your response. For matching

items, place the letter of your response in the space provided.

Item 1

The M240G is used to support both

a. offensive and defensive operations.

b. desert and jungle operations.

c. combat and training operations.

d. Army and Marine Corps operations.

Item 2

The weight of the M240G without the mount and tripod is _______ pounds.

20.6

25.6

26.5

29.5

Item 3

The maximum effective range of the M240G against an area target is

________ meters.

1400

1600

1800

2000

Continued on next page

MCI Course 0321B

R-1

Review Lesson Examination

Review Lesson, Continued

Items 4

Matching: For items 4 through 7, use the illustration below to match the

Through 7

group in column 2 with its item number in column 1.

Column 1

Column 2

Item

Group

_____ 4.

a. Receiver

_____ 5.

b. Buttstock

_____ 6.

c. Operating

_____ 7.

d. Barrel

Items 8

Matching: For items 8 through 11, match the purpose in column 2 with its

Through 11

group in column 1.

Column 1

Column 2

Group

Purpose

_____ 8. Barrel group

a. Controls firing

_____ 9. Buttstock group

b. Houses the action of the weapon

_____ 10. Trigger housing group

c. Directs the projectile after firing

_____ 11. Receiver group

d. Absorbs recoil

Continued on next page

MCI Course 0321B

R-2

Review Lesson Examination

Review Lesson, Continued

Item 12

The M240G uses the ________ tripod.

a. M2

b. M3

c. M122

d. M112

Item 13

Which tool is used to clean the gas ports on the barrel and gas regulator plug?

a. Combination tool scraper and extractor

b. Scraper tool

c. Cleaning rods and attachments

d. Reamers

Item 14

In the cycle of operations for the M240G, what follows firing?

a. Chambering

b. Ejecting

c. Extracting

d. Unlocking

Item 15

When clearing the M240G, you need to raise the feed tray and

a. visually and physically inspect the chamber for ammunition.

b. have an NCO check the weapon for ammunition.

c. remove the barrel to check for ammunition.

d. physically inspect the chamber for ammunition.

Item 16

The two types of disassembly are

a. dynamic and static.

b. field and garrison.

c. combat and armory.

d. general and detailed.

Continued on next page

MCI Course 0321B

R-3

Review Lesson Examination

Review Lesson, Continued

Item 17

Detailed disassembly of the receiver group includes removing the

a. bipod assembly.

b. charging handle.

c. cover and feed tray.

d. rear sight assembly.

Item 18

When assembling the M240G, you must assemble the ________________

and __________________ before the buttstock.

a. bipod assembly; operating group

b. trigger housing group; operating group

c. trigger housing group; barrel assembly

d. tripod; flex-mount

Item 19

A function check should always be performed

a. after firing the weapon.

b. before loading the weapon.

c. after the weapon has been disassembled and assembled.

d. before mounting on the tripod.

Item 20

The first step in performing a function check for the M240G is to

a. place the safety on SAFE.

b. place the safety on FIRE.

c. pull the cocking handle to the rear.

d. open the cover.

Item 21

The M240G uses _______________________ ammunition.

5.56 millimeter

7.62 millimeter

40 millimeter

.50 caliber

Continued on next page

MCI Course 0321B

R-4

Review Lesson Examination

Review Lesson, Continued

Items 22

Matching: For items 22 through 25, match the purpose in column 2 with the

Through 25

ammunition in column 1.

Column 1

Column 2

Ammunition

Purpose

_____ 22. M80 ball

a. Practice of loading and unloading

_____ 23. M62 tracer

b. Observation of fire and signaling

_____ 24. M82 blank

c. Anti-personnel and marksmanship

_____ 25. M63 dummy

training

d. Simulated live fire

Item 26

When storing M240G ammunition outdoors for long periods, it should be

kept at least ________ inches off the deck.

Item 27

Ammunition that is heavily corroded should be

a. fired immediately.

b. returned to the manufacturer.

c. thrown away.

d. replaced with clean ammunition.

Item 28

The only cleaning agents authorized for use on the M240G are

a. CLP, RBC, and dry cleaning solvent.

b. CLP, LAW, and LSA.

c. LSA-T, RBC, and gasoline.

d. LSA-T, LAW, and JP5.

Continued on next page

MCI Course 0321B

R-5

Review Lesson Examination

Review Lesson, Continued

Item 29

The only lubricants authorized for use on the M240G are

a. CLP, RBC, LAW, and WD-40.

b. LAW, LSA, LSA-T, and WD-40.

c. CLP, LAW, LSA, and LSA-T.

d. LAW, LSA, WD-40, and LSA-T.

Item 30

When environmental temperatures are normally below 10°F, the lubricant that

should be used on the M240G is

a. CLP.

b. LSA.

c. LAW.

d. LSA-T.

Item 31

When cleaning the M240G, avoid getting lubricants or solvents

a. on wooden parts.

b. on composite or rubber parts.

c. inside the receiver.

d. on the barrel.

Item 32

The scraper tool is used to clean

a. the barrel chamber and bore.

b. the receiver.

c. the operating rod.

d. the gas regulator plug.

Item 33

The driving spring should be replaced if there are __________ or more

broken strands on a single coil or ___________ or more broken strands

anywhere on the spring.

1; 3

1; 4

2; 3

2; 4

Continued on next page

MCI Course 0321B

R-6

Review Lesson Examination

Review Lesson, Continued

Item 34

Before firing the M240G, you should

a. remove excess lubrication from the bore, chamber, barrel socket, and face

of the bolt.

b. add extra lubrication to the bore, chamber, barrel socket, and face of the

bolt.

c. remove the lubrication from the spring pin, roller, and other moving parts

of the bolt.

d. remove the lubrication from the receiver rails.

Item 35

To check the headspace on the M240G, rotate the barrel handle to the “down”

position and count the number of clicks. There should be

1 to 7 clicks.

2 to 7 clicks.

2 to 8 clicks.

3 to 6 clicks.

Item 36

When caring for the M122 tripod, inspect the

a. rear legs for expanding properly and locking in place.

b. tripod head for missing paint.

c. mil scale on the rear legs for serviceability.

d. front leg locking pin for serviceability.

Item 37

When caring for the flex-mount/T&E mechanism, be sure to

a. extend the T&E mechanism all the way to clean the upper and lower

elevating screws.

b. rotate the traversing hand wheel to ensure no clicks are heard.

c. rotate the elevating hand wheel to ensure no clicks are heard.

d. check the functioning of the pintle lock.

Continued on next page

MCI Course 0321B

R-7

Review Lesson Examination

Review Lesson, Continued

Item 38

When caring for the carrying bag, be sure to wash the bag

a. using a washing machine dry with a dryer.

b. with hot water and detergent.

c. with chlorine bleach and solvents to remove lubricant stains.

d. with cold water and mild detergent.

Item 39

To release the bipod from the receiver, press the

a. bipod latch.

b. bipod lever.

c. barrel release.

d. slide latch.

Item 40

When setting up the tripod for use, extend the rear legs until the __________

latch engages, locking the legs in place.

a. sleeve

b. leg locking

c. bipod

d. tripod

Item 41

When preparing the T&E mechanism for use with the tripod, extend the upper

and lower elevating screws so that __________________ are visible on both.

1 1/2 inches

2 inches

2 1/2 inches

2 3/4 inches

Continued on next page

MCI Course 0321B

R-8

Review Lesson Examination

Review Lesson, Continued

Items 42

Matching: For items 42 through 45, match the description in column 2 to the

Through 45

weapon condition in Column 1.

Column 1

Column 2

Condition Code

Description

_____ 42.

a. The bolt is forward, the safety is

_____ 43.

disengaged, and the feed tray is clear of

_____ 44.

ammunition. The cover is closed.

_____ 45.

b. The bolt is forward, the chamber is

empty, and the safety is disengaged.

Ammunition is on the feed tray, the

cover is closed.

c. The bolt is locked to the rear, the safety

is engaged. Ammunition is on the feed

tray, the cover is closed.

d. Does not apply to the M240G.

Item 46

To load the M240G with the cover opened, place the belt of ammunition on

the feed tray with

a. closed side of the links facing down.

b. the links removed from the belt.

c. open side of the links facing up.

d. open side of the links facing down.

Item 47

When loading the M240G with the cover closed, the bolt should be

a. forward with the safety on SAFE.

b. to the rear with the safety on SAFE.

c. forward with the safety on FIRE.

d. to the rear with the safety on FIRE.

Continued on next page

MCI Course 0321B

R-9

Review Lesson Examination

Review Lesson, Continued

Item 48

When unloading the M240G, be sure to

a. center the T&E on the traversing slide bar.

b. raise the feed tray and inspect the chamber and receiver for rounds or

links.

c. leave the bolt forward so no additional rounds are chambered.

d. leave the safety on FIRE.

Item 49

The rapid rate of fire is 200 rounds per minute which equates to firing

6- to 8-round bursts with a 2- to 3-second pause.

6- to 8-round bursts with a 3- to 4-second pause.

10- to 12-round bursts with a 2- to 3-second pause.

10- to 12-round bursts with a 3- to 4-second pause.

Item 50

Placing the rear sight in the horizontal (“down”) position is for targets at

ranges

a. greater than 1000 meters.

b. less than 1000 meters.

c. greater than 800 meters.

d. less than 800 meters.

Item 51

When adjusting the rear sight in the vertical position, the range scale has

settings from 800 (8) to 1800 (18) meters in increments of ______ meters.

100

200

Continued on next page

MCI Course 0321B

R-10

Review Lesson Examination

Review Lesson, Continued

Item 52

Sight alignment for the M240G with the rear sight in the horizontal position

consists of aligning the tip of the front sight

a. blade in the center of the peep sight aperture.

b. blade with the center of the bottom of the peep sight aperture.

c. post with the center of the rear sight groove.

d. post with the center of the peep sight aperture.

Item 53

Which illustration shows the proper sight alignment with the rear sight in the

vertical position?

Item 54

When firing from the bipod, place the

a. right hand on the stock and the left hand on the pistol grip.

b. left hand on the stock and the right hand on the pistol grip.

c. right hand under the receiver and the left hand on the pistol grip.

d. left hand under the receiver and the right hand on the pistol grip.

Continued on next page

MCI Course 0321B

R-11

Review Lesson Examination

Review Lesson, Continued

Item 55

When firing from the tripod, the ___________ hand is on the pistol grip and

the ___________________________ hand wheel.

a. right; left hand is on the traversing

b. left; right hand is on the traversing

c. right; left hand is on the elevation

d. left; right hand is on the elevation

Item 56

To change direction using the T&E mechanism, rotate the

a. traversing hand wheel front or back with the left hand.

b. traversing hand wheel front or back with the right hand.

c. elevation hand wheel left or right with the left hand.

d. elevation hand wheel left or right with the right hand.

Item 57

Barrel changes should be done every __________ minutes when firing at the

sustained rate of fire.

Item 58

To remove the barrel from the receiver, press the barrel

a. locking latch.

b. release latch.

c. locking lever.

d. release lever.

Continued on next page

MCI Course 0321B

R-12

Review Lesson Examination

Review Lesson, Continued

Item 59

After unlocking the restraining strap on the front sight assembly, use the

___________________________ to adjust the front sight blade for elevation.

a. hex end of the combination tool

b. hex end of the front sight adjusting tool

c. slotted end of the combination tool

d. slotted end of the front sight adjusting tool

Item 60

When adjusting the windage on the front sight assembly, how many clicks are

there in one complete revolution of the adjusting screws?

Item 61

When conducting a BZO for the M240G, the target is 12.7 meters away and

the rear sight is set to ________ meters.

300

400

500

800

Item 62

When conducting a field expedient zero, one full turn of the front sight blade

moves the impact of the round _______________ inches for every 100

meters.

2 1/4

4 1/4

Continued on next page

MCI Course 0321B

R-13

Review Lesson Examination

Review Lesson, Continued

Item 63

The ___________ field of view on the AN/PAS-13B has a 5 × magnification.

a. narrow

b. wide

c. day

d. night

Items 64

Matching: For items 64 through 67, match the function in column 2 with its

Through 67

component in column 1.

Column 1

Column 2

Component

Function

_____ 64. Telescope

a. Processes the thermal image for

_____ 65. Sensor assembly

display

_____ 66. Eyepiece

b. Universal attachment interface

_____ 67. Mount

between the MWTS and the weapon

c. Provides magnification of the thermal

image

d. Displays the thermal image and all

system indicators for the operator

Items 68

Matching: For items 68 through 71, match the function in column 2 with the

Through 71

control in column 1.

Column 1

Column 2

Control

Function

_____ 68. Contrast knob

a. Selects the field of view

_____ 69. Brightness knob

b. Adjusts the focus of the reticle

_____ 70. Diopter

c. Used to turn power on and off

_____ 71. FOV knob

d. Adjusts the contrast of the thermal

scene

Continued on next page

MCI Course 0321B

R-14

Review Lesson Examination

Review Lesson, Continued

Items 72

Matching: For items 72 through 75, match the function in column 2 with the

Through 75

indicator in column 1.

Column 1

Column 2

Indicator

Function

_____ 72. NOT COOL

Displays when battery power is low

_____ 73. LOW BAT

Indicates the selected polarity

_____ 74. WHT HOT/BLK

Displays when the system has not

HOT

cooled down sufficiently

_____ 75. EMER

d. Displays when system is in

emergency mode

Item 76

The _____________________________ is used zeroing the sight and as a

tool for measuring angles in mils.

a. zeroing aim line

b. zeroing aim point

c. range gauge

d. aiming point

Item 77

When mounting the AN/PAS-13B to the M240G, align the mounting rail of

the sight with the _____________ slot from the rear of the mounting rail on

the weapon.

a. second

b. third

c. fourth

d. fifth

Item 78

To open the battery door, push in on the latch and rotate it

a. clockwise.

b. counterclockwise.

c. forward.

d. backward.

Continued on next page

MCI Course 0321B

R-15

Review Lesson Examination

Review Lesson, Continued

Item 79

When operating the AN/PAS-13B, place the eye against the eyecup and push

in to

a. activate the display.

b. power on the sight.

c. to change the field of view.

d. auto-focus the display.

Item 80

How much does the AN/PVS-17C weigh with a battery installed?

2 pounds

3 pounds

4 pounds

5 pounds

Item 81

What type of battery does the AN/PVS-17C use?

a. AAA cell

b. AA cell

c. C cell

d. D cell

Items 82

Matching: For items 82 through 85, match the function in column 2 with the

Through 85

component in column 1.

Column 1

Column 2

Component

Function

_____ 82. Objective lens

a. Provides magnification for the

_____ 83. Image intensifier

imager

_____ 84. Eyeguard

b. Protects the image intensifier

_____ 85. Daylight filter

during daylight use

c. Amplifies available light into a

viewable image

d. Provides light security to within

10 meters from the sight

Continued on next page

MCI Course 0321B

R-16

Review Lesson Examination

Review Lesson, Continued

Items 86

Matching: For items 86 through 89, match the function in column 2 with the

Through 89

control in column 1.

Column 1

Column 2

Control

Function

_____ 86. OFF-ON-ON switch

a. Provides power while it is held

_____ 87. Momentary button

_____ 88. Reticle brightness

b. Controls the power for the sight

_____ 89. Reticle adjustment

c. Used during zeroing to adjust

windage and elevation

d. Adjusts the reticle at five levels

Item 90

After mounting the AN/PVS-17C to the mounting rail on the M240G, you

need to check

a. safety on the weapon.

b. battery level.

c. polarity of the sight.

d. the eye relief and adjust if necessary.

Item 91

For the AN/PVS-17C to operate effectively,

a. some night light such as moonlight or starlight is needed.

b. it must be below 60º F outside.

c. it must be mounted on a weapon.

d. the objective lens cover needs to be installed.

MCI Course 0321B

R-17

Review Lesson Examination

Review Lesson, Continued

Answers

The table below lists the answers to the review lesson examination item. If

you have questions about these items, refer to the reference page.

Item Number

Answer

Reference Page

1-5

1-6

1-7

1-8

1-9

1-11

1-13

1-14

1-17

1-19

1-32

1-34

1-42

1-44

1-46

1-54

1-55

1-56

2-4

2-5

2-11

2-12

2-19

Continued on next page

MCI Course 0321B

R-18

Review Lesson Examination

Review Lesson, Continued

Answers,

continued

Item

Answer

Reference

Number

Page

2-24

2-30

2-31

2-32

3-4

3-7

3-9

3-20

3-21

3-22

3-30

3-31

3-32

3-33

3-34

3-35

3-37

3-49

3-50

3-51

3-53

4-5

Continued on next page

MCI Course 0321B

R-19

Review Lesson Examination

Review Lesson, Continued

Answers,

continued

Item

Answer

Reference

Number

Page

4-5

4-6

4-7

4-10

4-11

4-12

4-13

4-18

4-19

4-21

4-24

4-25

MCI Course 0321B

R-20

Review Lesson Examination

THE M240G MACHINEGUNNER. Maintenance Manual MCI 0321B (2007) - page 2