seabeecombat warfare common core unit 108 weapons fundamentals navedtra 43904-c

SEABEE SEABEE COMBAT COMBAT WARFAREWARFARE

COMMON CORECOMMON CORE

Unit 108Weapons Fundamentals

NAVEDTRA 43904-C

Weapons Fundamental Reference

• (a) NAVEDTRA 14234, Seabee Combat Handbook, Vol 1• (b) NAVEDTRA 14324, Gunner’s Mate• (c) Seabee Battle Skills Guide, Vol 1• (d) NTRP 3-07.2.2• (e) Construction Battle Skills Guide, Book 1, All Hands 2005• (f) TM-SW215-BC-MMO-010, Operator’s and Maintenance Manual for

AN/PVS-12A, Night Vision, Crew Served Weps• (g) FM 3-22.09, M16A1 and M16A2 Rifle Marksmanship

(h) TM-SW215-B4-MMO-010, Operator’s and Maintenance Manual for AN/PVS-12A, Night Vision, Individual Weapon

• (i) Construction Battle Skills Guide, Book 4, Crew/Team Skills 2005 Edition(j) TM 9-1010-230-10, Operators Manual Machine Gun, 40mm, MK19, MOD3(k) TM 9-1005-213-10, Operators Manual Machine Gun, Cal. 50, Browning M2, Heavy Barrel Ch. 1, sec II pg 1-5(l) FM 3-22.68(m) MCWP 3-15.1 Machine Guns and Machine Gunnery

4 RULES OF WEAPONS SAFETY

• PQS Question 108.1 State the four rules of weapons safety.

• Reference: (c, Ch 1) Seabee Battle Skills Guide, Vol. 1

4 RULES OF WEAPONS SAFETY

• Rule 1 – Treat every weapon as if it were loaded.

• Rule 2 – Never point a weapon at anything you do not intend to shoot.

• Rule 3 – keep finger straight and off the trigger until you are ready to fire.

• Rule 4 – Keep weapon on SAFE until you intend to fire.

WEAPON CONDITIONS

• PQS Question 108.2 State the four weapon conditions

• Reference: (c, Ch 1)Seabee Battle Skills Guide, Vol. 1

WEAPON CONDITIONS

• Condition one– Magazine is inserted, a round must be chambered, and the safety

is on.• Condition two

– Magazine is inserted, a round is chambered, the weapons action is closed, and the hammer is forward. This condition applies to weapons with external hammers except for the M9 service pistol.

• Condition three– Magazine is inserted, chamber is empty, the action is closed and

safety is on.• Condition four

– All ammo is removed, chamber is empty, the action is closed and the safety is on.

NCF Weapons System

• PQS Question 108.3 What weapons systems are in the NCF?

• Reference: [ref: l, ch. 3, ref: b, ch. 3]

NCF Weapons System

• M9• M16• M240B• 50 Cal• MK 19• AT4• M-203• M-500 Shotgun

Define the following terms

• PQS Question 108.4 Define the following terms associated with the M16A3 and the M9.

• Reference: (a, ch. 3) NAVEDTRA 14234, Seabee Combat Handbook, Vol 1

Malfunction & Misfire

• Malfunction– The failure of a weapon to function satisfactorily, usually because of excess

friction caused by dirt, improper lubrication or carbon buildup.– Immediate action- you must stop and clean the weapon to correct this problem

• Misfire– A complete failure to fire, NOT a delay in firing that may be caused by a faulty

firing mechanism or a faulty element in the propelling charge explosive train.– Immediate action

• Strike the forward assist to be sure the extractor has engaged a round• Tap upward on the magazine to ensure it is fully seated.• Pull the charging handle to the rear.• If round is ejected, release handle, strike forward assist and attempt to fire.• If round is not ejected, check for a round in the chamber, if it is clear,

release handle, strike forward assist and attempt to fire.• If a round is stuck in the chamber it must be removed before attempting to

reload/ re-chamber.

Stoppage

Stoppage• Any interruption in the cycle of functioning caused by faulty

action of the weapon or ammunition.• Immediate action• Strike the forward assist to be sure the extractor has engaged a

round.• Tap upward on the magazine to ensure it is fully seated.• Pull the charging handle to the rear.• If round is ejected, release handle, strike forward assist and

attempt to fire.• If round is not ejected, check for round in the chamber, if it is

clear, released handle, strike forward assist and attempt to fire.• If a round is stuck in the chamber it must be removed before

attempting to reload/re-chamber.

Firing Cycle

• PQS Question 108.5 State the eight operation in a firing cycle.

Reference: [b, ch. 3]NAVEDTRA 14324, Gunner’s Mate

Firing Cycle

• Feeding: the feeding action places a round in the receiver just to the rear of the chamber.

• Chambering: takes place as the moving bolt strips the round and forces it into the chamber.

• Locking: holds the bolt in the forward position for a short period of time to prevent the loss of gas pressure.

• Firing: the firing pin actually strikes the primer of the cartridge• Unlocking: after the round is fired, the bolt unlocks and moves rearward.• Extracting: the process of pulling the empty case back out of the chamber. As

the bolt moves rearward extraction occurs.• Ejecting: as the casing is extracted, ejection occurs as it is thrown out of the

weapon.• Cocking: the retraction of the firing mechanism against spring pressure so that

there will be sufficient energy to fire the next cartridge.

Semi/Auto operations

• PQS Question 108.6 Explain the differences between semi-automatic and automatic operations

Reference: [a, ch. 3]NAVEDTRA 14234, Seabee Combat Handbook, Vol 1

Differences SEMI/AUTO

• A semiautomatic weapon unlocks, extracts, ejects, cocks and reloads automatically. The trigger must be pulled each time to fire a round.

• An automatic weapon unlocks, extracts, ejects, cocks and reloads automatically. An automatic weapon will fire as long as the trigger is pulled and rounds are available to fire.

Terminology

• PQS Question 108.7 Define the following terms [ref a]

• Trajectory [ch. 3] • Breech [app. L]• Bore [ch. 3]• Chamber [app l]• Muzzle [app l]• Muzzle Velocity [app l]• Maximum Range [ref b, ch. 3]• Maximum Effective Range [ref b, ch. 3]

Terminology

• Trajectory: The flight path the bullet takes from the weapon to the target.

• Breech: The rear end of the barrel.• Bore: The actual hole in the barrel. It may be rifled or not.• Chamber: The enlarged part of the bore at the breech that holds the

cartridge.• Muzzle: The front or forward end of the barrel.• Muzzle velocity: The speed at which the bullet travels when it leaves

the muzzle.• Maximum range: The greatest distance a round will travel• Maximum effective range: The greatest distance at which a weapon

may be expected to fire accurately to inflict damage or casualty.

Ammunition Color Codes

• PQS Question 108.8 Discuss small arms ammunition color codes and state the purpose of each:

Orange or red [ref a, ch. 3]Violet [ref a, ch. 3]Black [ref a, ch. 13]Aluminum [ref a, ch. 13]Green [ref a, ch. 3]

Reference: NAVEDTRA 14234, Seabee Combat Handbook, Vol 1.

Ammo Color Codes

• Orange or red: Tracer rounds• Violet: Blank rounds• Black: Armor piercing• Aluminum: Armor piercing, incendiary.• Green: Standard ball ammunition

Maximum Ranges

• PQS Question 108.9 State the maximum range, maximum effective range, employment, rates of fire, and types of ammunition of the following weapons: [ref i]

M9 Service PistolM1-16A3 rifle

Reference: (i) Construction Battle Skills Guide, Book 4

Describe the 9mm

• 9mm pistol– semi-automatic– Magazine fed– Recoil operated– Double action or single action firing pistol– Current issue sidearm– Capabilities/Characteristics– Length: 8.54in– Weight: 2.12lbs– Weight fully loaded (15rnd mag): 2.54lbs– Magazine capacity: 15 rounds– Muzzle velocity: 1230/fps– Max effective range: 50m– Ammunition: fires 9mm Ball ammunition– Safety Features

• The M9 pistol has only ONE safety.• It has THREE SAFETY FEATURES.

– Ambidextrous safety: Allows for safe operation of the pistol by right and left handed users. Lowers the hammer safely without causing an accidental discharge

– Firing Pin Block: Prevents any motion of the firing pin and is only overcome by pulling the trigger– Half Cock Notch: Prevents accidental discharge. If the cocked hammer should fall forward due to a

mechanical failure, this would catch on the sear before the hammer would strike the firing pin.

Describe the M-16A3

• M-16 rifle– Lightweight– Gas operated– Air cooled– Magazine fed– Shoulder fired– Semi-automatic or fully automatic– Modes of fire

• Semiautomatic Fire Mode: When a single shot is fired the trigger must be pulled each time.• Automatic Fire mode: Rifle will continue to fire as long as the trigger is held back

– Selector Level• Safe Position: Rifle will not fire• Semi position: The trigger must be pulled each shot• Auto: Rifle will continue to fire as long as the trigger is held back

– Capabilities/Characteristics• Length w/flash suppressor: 39in• Length of barrel w/flash suppressor: 21in• Weight: 7.8lbs• Weight fully loaded (30 round ma): 8.79lbs• Magazine capacity: 20/30 rounds• Muzzle velocity: 3100/fps• Max range: 3534m• Max effective range: Point Target 550 and Area Target 800m

– Rates of Fire• Sustained: 12 to 15 rounds per minute• Rapid: 150 to 200 rounds per minute• Cyclic: 700 to 800 rounds per minute

– Ammunition• 5.56 Ball: Standard round• 5.56 Tracer: Used to mark targets or cause incendiary effects• 5.56 Blank: Training round• 5.56 Dummy: Totally inert training

Loading/Unloading

• PQS Question 108.10 Discuss loading/unloading procedures for the following weapons:

M9 Service Pistol [ref b, ch. 3]M-16A3 rifle [ref a, ch. 3]

• Reference: (a) NAVEDTRA 14234(b) NAVEDTRA 14324

Proper Loading/Unloading

• 9mm pistol./ M-16 rifle– Keep safety in “safe” position until ready to fire.– Keep muzzle down range and clear of all troops– Before loading, make sure bore, chamber, and ammunition are

clean and dry.– Hold the pistol at the raised pistol position, or place the rifle butt

against the thigh– Then, remove the magazine by pressing the magazine catch or

release button.– To make absolutely certain the chamber is empty, pull back the

slide or bolt and inspect the chamber and verify visually. If it is dark, feel to check. Opening the slide or bolt will eject any round that may have been in the chamber.

TYPES OF GRENADES

• PQS Question 108.11 Describe and discuss the six types of grenades: [ref. a, ch. 12].

• Reference: (a, Ch 12) NAVEDTRA 14234, Seabee Combat Handbook, Volume 1

Grenades

• Fragmentation– Grenades designed to inflict personnel casualties and damage to light equipment by

projecting high velocity fragments from the detonated grenade case– The effective casualty-producing radius is about 15 meters

• Illumination– Used to illuminate terrain in night time operations– Once pin is pulled, GRENADE MUST BE THROWN!– Grenades used mainly to light up the terrain.– The MK 1 is the only illuminating grenade currently available.– It provides about 55,000 candlepower for a period of 25 seconds.

• Chemical– Used for incendiary, screening, signaling, training, and riot control purposes– Grenades that are chemical filled munitions designed to be thrown by the individual or

projected from the service rifle using a special adapter.– ABC-M25A2, riot control hand grenade is the most commonly used.

• Filled with a type of tear gas chemical that causes irritation and watering eyes.

Grenades

• Incendiary– AN-M14 incendiary Thermite grenade is used to ignite combustible materials and to

destroy all types of equipment.– This TH grenade is cylindrical in shape and weights 32 ounces.– Contains filler of 26.5 ounces of Thermite mixture– It uses an igniting delay fuse that sets fire to the Thermite– The Thermite burns at a temperature of about 4,300 deg F

• Smoke– Grenades that are cylindrical in shape and weigh about 27 ounces.– They can be thrown about 40 yards with an effective casualty radius of nearly 30 yards

• Practice/training– Used to train personnel in the care, handling, and use of grenades prior to using actual

service grenades.– These grenades are used for training personnel in the care, handling, and use of hand

grenades before using service grenades.– Practice grenades simulate the functioning of service grenades to provide realism in

training.

Hand Grenade Safety Procedures

• PQS Question 108.12 Discuss hand grenade safety procedures. [ref. a, ch. 12]

• Reference: (a, Ch 12) NAVEDTRA 14234, Seabee Combat Handbook, Volume 1

Hand Grenade Safety Procedures

• All personnel handling casualty producing grenades must wear proper protection

• Never attempt to defuse hand grenades• Do not remove the safety pin until ready to

throw• Do not attach grenades to clothing or

equipment.

CLAYMORE

• PQS Question 108.13 Discuss the placement, arming, safety requirements, coverage, and methods of firing the Claymore mine. [ref. a, ch. 12]

• Reference: (a, ch. 12) NAVEDTRA 14234, Seabee Combat Handbook, Vol. 1

Claymore Mines

• Placement– This mine should be positioned so as to afford all friendly personnel, within 100 meters to

the rear and sides of the mine, the opportunity to take adequate cover.• Arming

– After the M18A1 mine is positioned and properly aimed, it is armed by first opening the blasting cap assembly and unrolling the wire from either the firing position or the mine.

– The wire is secured by wrapping a few turns of wire around a leg of the mine and burying it, if possible.

• Safety requirements– Before attaching the firing device directly, the circuit should be checked for continuity with

the test set provided to ensure that the mine will function at the desired time– The firing device has a safety bail with two positions– In the upper (safe) position, it acts as a block between the firing handle and the generator.– In the lower (fire) position, it allows the generator to be activated.– The instructions provided with the M7 bandoleer should be carefully followed by anyone

using these mines.

Claymore Mines

• Range/Coverage– When detonated, the M18A1 mine will project steel spheres over a 60 degree

fan shaped pattern approximately 6 feet high and 50 meters wide to an optimum effective range of 50 meters

– These steel fragments re moderately effective up to a range of approximately 100 meters and can travel up to 250 meters

• Method of firing– M18A1 mine can be in either an uncontrolled or a controlled role. An

uncontrolled mine is essentially a booby-trap. This use by Seabees is not authorized. In a controlled role, the operator detonates the mine as the enemy approaches within the killing zone

– By using either an electrical or a non-electrical firing system, the operator can control detonation.

– In almost all cases, mines employed by Seabees will be fired electrically with the M57 firing device.

M240B

• PQS Question 108.14 Explain the characteristics of the machine gun [ref l, ch. 3]

Reference: FM 3-22.68

M240B

• Air-cooled, Belt-fed, Gas-operated, Fully Automatic weapon, Fires from open bolt Position and is Crew served – Length................................49 inches– Weight ...............................27.6 pounds– Maximum range ................3,725 meters

Loading/Unloading

PQS Question 108.15 Discuss loading/unloading procedures [ref l, ch. 3]

Reference: FM 3-22.68

Loading/Unloading

• The M240B machine gun is loaded from the closed bolt position. The M240B is fired, unloaded, and cleared from the open bolt position. The safety must be placed on “F” before the bolt can be pulled to the rear. Before belted ammunition can be used, it must be linked with the double link at the open end of the bandoleer. It must be free of dirt and corrosion.

• Loading – Two methods, raised cover and closed cover– Raised cover method – preferred method

• Gunner ensure the bolt is to the rear and the safety lever is on safe (S)• Gunner raises the cover• Team leader places the first round of the bandoleer and places it over the feed aperture• Gunner then closes the cover and places the safety lever on fire (F)• Weapon is now loaded and ready to fire

– Closed cover method – alternate method• Gunner ensures bolt is forward safety lever is on fire (F) and the cover remains closed• Team leader takes a bandoleer of ammunition and inserts the first round into the feedtray• The weapon is now loaded• Gunner pull bolt to the rear and slides cocking handle forward – The weapon is now ready to

fire

Loading/Unloading

• Unloading– Gunner ensures bolt is to the rear and the safety is on

safe (S)– Gunner raises the cover– Team leader removes the ammunition and links from the

feedtray– Gunner then raises the feedtray and visually inspects the

receiver and chamber to ensure no rounds remain– Once the feedtray, receiver and chamber have been

cleared of all ammunition and links the weapon is considered to be unloaded

Capabilities/Nomenclature

• PQS Question 108.16 State the following capabilities/nomenclature

Proper employment [ref l, ch. 3]FPL/PDF [ref l, ch. 5]Maximum effective range [ref l, ch. 3]Safeties M240B [ref l, ch. 3]Ammunition types [ref l, ch. 3]Rates of fire [ref l, ch. 3]Types of mounts [ref l, ch. 3]

Capabilites/Nomenclature

• Proper employment – Analyze the operation order using METT-T SALUTE DRAW-D and KOCOA– Consider the characteristics of the machine guns to be employed– Consider employment of the machine guns in defense– Consider employment of machine guns in the offense– Direct the employment of the machine guns

• Final Protective Line (FPL)/Principal Direction of Fire (PDF) – Assignment of a Final Protective Line (FPL)

• Position machine guns to the flanks to provide fire across the unit's front.

• Ensure the position provides interlocking grazing fires within an assigned sector

• Ensure that FPL dead space can be covered by alternate weapons (munitions, M203 grenade launchers, mortars, claymore mines)

– Assignment of a Principal Direction of Fire (PDF)• Ensure the position covers likely avenues of approach and obstacles

– Maximum effective range: 1,100 meters with tripod and T&E

Nomenclature

• Area– Tripod..................................................1,100 meters– Bipod...................................................800 meters

• Point– Tripod..................................................800 meters– Bipod...................................................600 meters– Suppression...............................................1,800 meters

– Safeties • The safety mechanism is located on the pistol grip just behind the trigger well.

When the safety is pushed to the right, the letter “S” is visible indicating the weapon is on safe. When pushed to the left, the letter “F” is visible on the safety indicating the weapon is on fire. The safety can only be engaged when the bolt is in the rear position. On the “S” position, the bolt cannot be released to go forward.

– Ammunition types• 7.62 mm ball• 7.62 mm tracer• 7.62 mm armor-piercing (not authorized for training)• 7.62 mm blank• 7.62 mm dummy

Rates of Fire

– Rates of fire• Sustained ..............................100 rounds per

minute fired in 6- to 9-round bursts and 4 to 5 seconds between bursts (barrel change every 10 minutes)

• Rapid......................................200 rounds per minute fired in 10- to 13-round bursts and 2 to 3 seconds between bursts (barrel change every 2 minutes)

• Cyclic ………………………….650 to 950 rounds per minute in continuous bursts (barrel change every minute)

Types of Mounts

– Types of mounts • M122A1 Tripod: provides a stable mount for the M240B,

and it permits a higher degree of accuracy and control. The tripod is recommended for marksmanship training and defensive employment. The M122A1 tripod consists of the tripod and flex-mount with T&E mechanism. Weight of M122A1 tripod with/flex-mount is 20 pounds.

• Bipod Assembly: used to fire from the prone position. The butt stock in conjunction with the gunner’s non-firing hand provides support for the weapon when firing in the bipod mode. The gas cylinder holds the bipod in place.

Members of a Gun Team

• PQS Question 108.17 Name the members of a gun team and state what they are responsible for carrying into a combat situation

• Reference: [ref a. p. 1-17]NAVEDTRA 14234, Seabee Combat Handbook, Vol 1

Gun Team

• Team leader– Usually a PO2, responsible for effective employment of the gun– Responsible for changing the barrels during firing– Carries spare barrel kit, M122 tripod, one bandoleer of ammo and armed

with a 9mm pistol• Gunner

– Usually a PO3. Actually fires and maintains the gun– Carries the gun, one bandoleer of ammo and armed with a 9mm pistol

• Ammo 1– Usually a CN, acts as the supply person for the team– Caries one box of ammo, spare barrel case with T&E. Armed with an M16

• Ammo 2– Usually a CA– Carries two boxes of ammo. Armed with an M16

Weapons Fundamentals

• PQS Question 108.18 Describe the characteristics of 40mm Machine Gun

• Reference: [j]TM 9-1010-230-10

40 mm Machine Gun

40 mm Machine Gun

• Air-cooled• Belt-fed• Blow back operated• Automatic weapon• Fires from open bolt position• Crew served


• PQS Question 108.19 Discuss loading/unloading procedures for the 40mm Machine Gun

• Reference: [j]TM 9-1010-230-10

40mm Machine GunLoading

• Keep the weapon down range

• Make sure the bolt is forward. If not take the weapon off safe and ease the charging handles forward.

• Open the cover

• Insert the first round through the feed throat


• Insert the first round through the feed throat

• Place the first round into the feeder. Female link first.

• Push the round across the first pawl

• Move the slide assembly to the left


• Close the cover

• Unlock and grasp the charging handles and charge weapon

40mm Machine GunUn-Loading

• Place weapon on safe

• Open cover

• Remove remaining rounds and inspect chamber

• Once clear, close cover

40mm Machine GunUn-Loading

• Place weapon on fire and use charging handles to “ride” bolt forward or press trigger sending the bolt forward.


• PQS Question 108.20 State the following capabilities/nomenclature of the 40mm Machine Gun.

* Proper employment [ref m, ch. 6, sec l]

* FPL/PDF [ref m, ch. 6, sec l]* Arming Range [ref j]* Maximum effective range – area [ref j]* Maximum effective range – point [ref j]* Rate of fire [ref j]* Safety [ref j]* Ammunition Types [ref j]


• Proper employment

– Conduct a leader's reconnaissance of the assigned area.

– Consider placing firing positions in areas where the mission can be accomplished.

– Look for mounted firing positions.

– Choose dismounted firing positions when the terrain prevents vehicles from moving into position or if the vehicle cannot be concealed.

– Identify firing positions.

– Move vehicle into position

– Ensure that the machine guns are properly laid.

– Ensure that the firing positions are properly prepared and occupied

– Ensure that range cards are prepared for each position.

FPL/PDF

• FPL/PDF

– NOTE: The MK19 heavy machine gun does not fire an FPL.

– Assign a Principal Direction of Fire (PDF)

• Assign a PDF only when the terrain does not allow for effective FPL fires.

• Ensure the PDF covers the most likely avenues of approach.

• NOTES: The PDF may fall within the sector of fire or comprise one of its boundaries.

– Location of machine guns must be changed daily/nightly or whenever needed.

40mm Machine Gun

• Arming range – M383 HE round: 18 to 36 meters– M918 TP round: 18 to 30 meters

• Maximum effective range – (area target) – 2212 meters– (point target) – 1500 meters

• Rate of fire – 325 to 375 rounds per minute• Safety

– Thumb switch with “Safe” and “Fire” positions• Ammunition types

M383 HE: High explosive, designed to inflict personnel casualties. Arming distance of 18 to 36 meters. 15 meter casualty radius– M430 HEDP: High explosive, dual purpose– M385E4 / M385A1: Training Practice with propellant. Maximum

range 2200 meters


• PQS Question 108.21 Describe the characteristics of the .50 caliber M2 machine gun

Reference: [k, ch. 1, sec ll, p. 1-5]TM 9-1005-213-10

M2 Machine Gun

M2 Machine Gun

• The .50-caliber machine gun is a belt-fed, crew-served, recoil-operated, air-cooled weapon.

• It can be set for automatic and semiautomatic fire.

• The weapon does not have any safeties.


• PQS Question 108.22 Discuss loading/unloading procedures for the M2 Machine Gun

• Reference: Reference: [k, ch. 1, sec ll, p. 1-5]TM 9-1005-213-10

M2 Machine Gun Loading

Automatic mode

• Make sure gun is clear• Close the bolt• Close feed cover• Lock down the bolt latch release• Insert the ammo


• Cock the gun (the gun is now “half-cocked”)• Re-cock the gun (now it is “fully-cocked”)


Single shot mode

• Make sure gun is clear• Close the bolt• Close feed cover• Rotate bolt latch release lock in the up

position to the right


• Insert the ammo

• Cock the gun (the gun is now “half-cocked”)

• Re-cock the gun (now it is “fully-cocked”)

• To fire another round you must push the bolt release allowing the bolt to go home

M2 Machine Gun Un-Loading

• Place the gun in single shot mode

• Pull slide handle to the rear and lock bolt rearward

• Open the feed cover

M2 Machine Gun Un-Loading

• Clear all remaining links or rounds

• Inspect chamber insuring it is clear

• Press the bolt latch release and ride the bolt forward

• Close the feed cover and pull the bolt to the rear


• PQS Question 108.23 State the following capabilities/nomenclatures

* Proper employment [ref m, ch. 6, sec l]* FPL/PDF [ref m, ch. 6, sec l]* Arming Range [ref m, ch. 6, sec l]* Maximum effective range – area [ref k, ch 1, sec ll, p. 1-9]* Maximum effective range – point [ref k, ch 1, sec ll, p. 1-9]* Direction of feed [ref k, ch 1, sec ll, p. 1-9]* Rates of fire [ref k, ch 1, sec ll, p. 1-9]


• Proper employment – Conduct a leader's reconnaissance of the assigned area.– Consider placing firing positions in areas where the mission can be

accomplished.– Look for mounted firing positions.– Choose dismounted firing positions when the terrain prevents

vehicles from moving into position or if the vehicle cannot be concealed.

– Identify firing positions.– Move vehicle into positions.– Ensure that the machine guns are properly laid.– Ensure that the firing positions are properly prepared and occupied.

If you must use a hide position, perform the following steps.– Ensure that range cards are prepared for each position.

M2 Machine Gun

• FPL/PDF – FPF

• Ensure that the FPL achieves the maximum flanking fire.• Ensure that the FPL obtains the maximum grazing fire. Grazing

fire should parallel the expected long axis of the enemy assault waves.

• Ensure interlocking fires are used to cover any gaps in the FPL and to provide mutual support between adjacent units.

• Employ obstacles to slow down the enemy when reaching the FPL, if possible.

– PDF• Assign a PDF only when the terrain does not allow for effective

FPL fires.• Ensure the PDF covers the most likely avenues of approach.

M2 Machine Gun

• Maximum range – 6800 meters (M2 Ball)• Maximum effective range – 1800 meters• Direction of feed – Load so double end loop

on ammo belt clicks into the feedway.• Rates of fire

– Sustained: 40 rounds (or less) per minute– Rapid: 40 rounds (or more) per minute– Cyclic: 450 – 550 rounds per minute


• PQS Question 108.24 Describe setting headspace and timing on the .50 caliber machine gun

• Reference: [k, ch. 2, sec lll, p. 2-39]TM 9-1005-213-10

M2 Machine GunHeadspace

Headspace - Distance between the bolt face and the base of a seated cartridge (rnd).

Correct when:

– Recoiling groups are fully forward

– No independent rearward movement between the bolt, barrel and barrel extension


–Must be checked and set before gun is fired,

–When barrel is replaced and

–When correct setting is in doubt


• Headspace Gauge

• Tool used to check and set headspace

• Has “GO-NO GO” reading

M2 Machine GunHeadspace Adjustment

• Insert the “GO” side of the gauge between the bolt and rear of the barrel (T-slot)

• The gauge should enter freely up to the center ring

• Remove the gauge and place the “NO-GO” side in the T-slot

• If the “NO-GO” side does not enter, the headspace is set correctly


• Headspace Too Tight• The “GO” side of the gauge cannot enter freely• Pull back on the charging handle• While holding it back, unscrew the barrel one

notch (click)• Ease the bolt forward • Recheck the headspace with the gauge


• Headspace Too Loose

• If it is too loose the “NO-GO” side of the gauge will enter freely

• To adjust it follow the same procedures as if it were to tight, but tighten the barrel

M2 Machine GunTiming

• Timing - Ensures that firing takes place when the recoiling parts are between .020 and .116 inch out of the battery (fully forward).

M2 Machine GunTiming

Correct when:

– recoiling parts are locked together

– Firing takes place just before the recoiling parts are in the battery

– The gun fires on the “FIRE” gauge

– And WILL NOT on the “NO-FIRE” gauge

M2 Machine GunTiming Adjustment

• Timing Adjustment

• Checked with the “FIRE” (.020 in) and “NO-FIRE” (.116 in) gauges

• Must be checked and/or set each time headspace is adjusted and whenever timing is questionable


• Timing Adjustment Steps

• Check headspace first• Ensure gun is cocked and bolt forward• Raise the extractor• Retract the bolt far enough to insert the

“FIRE” gauge


• Timing Adjustment Steps Continued

• Place it between the extension and the trunnion block

• Allow the barrel extension to close on the gauge

• Depress the trigger, the firing pin should release


• Retract the bolt far enough to remove the “FIRE” gauge, cocking the gun and allow the bolt to go forward

• Retract the bolt far enough to insert the “NO-FIRE” gauge, place it in the same position

• Depress the trigger, the firing pin should not release


• Timing Late

• The firing pin will not release when the “FIRE” gauge in in place. If this happens perform the following:

• Remove “FIRE” gauge


• Remove backplate assembly

• Locate and turn the trigger bar adjusting nut one notch to the right

• Reinstall the backplate assembly

• Reinsert the “FIRE” gauge and test again


• Timing Early

• The firing pin will release when the “NO-FIRE” gauge in in place. If this happens perform the following:

• Perform the same steps as if it were late except turn the trigger bar adjusting nut on notch to the left


• PQS Question 108.25 Describe the characteristics of the 40mm M203 grenade launcher

• Reference: [i] Construction Battle Skills Guide, Book 4, Crew/Team Skills

40mm Grenade Launcher

40mm Grenade Launcher

• Description

– Light weight

– Single shot

– Breech loaded

– Pump action

– Shoulder fired weapon

– Attaches to the M16 rifle


• PQS Question 108.26 State the following capabilities/nomenclature

* Proper Employment* Ammunition Type* Maximum effective range (area)* Maximum effective range (point)* Maximum range

• Reference: [a] NAVEDTRA 14234, Seabee Combat Handbook, Vol. 1.

Capabilites/Nomenclature

– Proper employment

• Place the weapon in condition 4

• Ensure that the M203 grenade launcher is assembled and functioning for firing.

• Select the correct ammunition.

• Place the weapon in condition 4.

• Use proper firing techniques.

• Field zero the M203 grenade launcher.

• Estimate range to target.

• Respond to fire commands.

• Engage targets effectively.

• Place the weapon in condition 4.

Capabilities/Nomenclature

– Ammunition type [ref. a, p. 13-4]• HE round

– Designed to inflict personnel casualties. 5 meter casualty radius with a danger radius of 30 meters. Arms within 14 meters to 27 meters.

• HE air burst– Lands on the deck and bounces up 2 meters to explode. Arms

within 14 meter to 27 meters.• HEDP

– High explosive, can penetrate 2” of steel. 5 meter casualty radius• TP

– Training rounds with flash signature. Danger radius of 20 meters.– Maximum range [ref. a, p. 13-1] – 400 Meters– Maximum effective range

• (area target) [ref. a, p. 13-1] – 350 Meters• (point target) [ref. a, p. 13-1] – 150 Meters


• PQS Question 108.27 Describe the characteristics of the M500 12-gauge shotgun

• Reference: [h, p. R3-19]TM-SW215-B4-MMO-010

M500 12 Gauge Shotgun

12-Gauge ShotgunOperation

• Manually operated• Single shot• Magazine feed (tubular)• Pump action• Shoulder fired weapon


• PQS Question 108.28 Describe loading and unloading procedures for the 12-gauge shotgun.


12-Gauge ShotgunLoading

• Single Load

• Ensure the weapon is on safe

• Press the action lock lever and slide barrel (fore-end) rearward


• Insert round into the barrel chamber

• Slide the barrel closed

• Weapon is now loaded


Magazine Load

• Ensure the weapon is on safe

• Slide barrel (fore-end) forward

• Insert round into the magazine

12-Gauge Shotgun

• Loading– Weapon is now loaded without round in

chamber– Open and close barrel to chamber a round

• Unloading– Open barrel to eject round to unload


• PQS Question 108.29 State the following capabilities/characteristics of the 12 gauge shotgun.– Length– Safeties– Ammunition type


12-Gauge Shotgun

• Length: 39 inches

• Safeties: Safety switch on top

• Ammunition type: 12 ga, 2 - 2 3/4 in 00 buck, military round


• PQS Question 108.30 Describe the use and purpose of the range card as it relates to each weapon system.

• Reference: [i, ch. 4] Construction Battale Skills Guide, Book 4

Range Cards

– Cards are the basis for the fire plan at the company level. Each crew served weapon will have one.

– All supporting fires, security sectors and defensive coordination are planned using the machine gun’s fire as the base from which to build.

Range Cards

– Two cards are prepared, one for the gun and the other goes to higher HQ.

– Cards should be passed on to relieving units.

– Patrols can use your card to locate FPL’s and identify dead space.

– Cards must be neat and prepared using a universal format.

Range Cards

• Gun Identification Block - Identifies what gun the card belongs to and the date it was drawn.

Gun #1Squad #3

"A" Co5-Apr-99

Range Cards

• Weapon Symbol - Single dot for the gun and a solid arrow extending out along the FPL or PDF.

Range Cards

• Magnetic Orientation Line and Location Grid Coordinates - A means for others to positively locate your gun position. The line is drawn from a prominent terrain feature that is located behind friendly lines. The grid coordinates are recorded next to the dot in the machine gun symbol.

Range Cards

• Sector Limits - Drawn as broken lines ending in arrow heads. If using an FPL only one sector limit will be drawn because one will be the same as the FPL.

Range Cards

• Grazing Fires - If an FPL is used, a heavy shaded area is drawn along the inside of the FPL. This will indicate the limits of grazing fire obtainable. Any dead space is shown by breaks in the shading. Record the near and far limits of the dead space in meters or record the range next to the ends of the shaded areas.

Range Card Symbols

• Terrain Features - Draw only those terrain features that significantly add to the clarity of the range card. If the feature is drawn, draw it to the correct perspective.

• Wooded area

hill

Range Card Symbols

• Location of Friendly Troops or Equipment - Draw any friendly positions or equipment that is either in or near the sector limits of the machine gun.

1st SqdWater tower

Range Card Symbols

• Targets - Draw targets to perspective and label them with a number.

– The number one target will be either the FPL or the left sector limit.

– If the FPL is on the right sector limit, number all other targets sequentially from right to left.

– All other times number from left to right.

Range Card Symbols

– One method is to record data directly on the sketch along the leading line to the target.

– The other method is to use the data block of the card.

Sample Range Card

• 2

1st Sqd

2nd Sqd 3rd Sqd

AB1001

300m

400m


• PQS Question 108.31 Discuss the integration of the weapons systems into an overall defensive fire plan.

• Reference: [i, ch. 4] Construction Battale Skills Guide, Book 4

• Automatic Rifleman– M16 rifle, backbone of the defense of the squad. Positioned first by

the squad leader. The remainder of the fire team is positioned around the AR.

• Rifleman– M16 rifle, positioned so they can cover the entire fire team sector.

The position must provide support and protection for the AR• Grenadier

– M203 grenade launcher, positioned to cover dead space in the defense

• M240B– Support the rifleman in the offense and defense. Provide heavy

volumes of controlled fire. Provide FPF’s. Cover likely avenues of approach. Provide grazing fire.

Weapons Systems Integration

Weapons Systems Integration

• M2 .50 Cal Machine Gun– Provide protection for motorized movement.

Destroy lightly armored vehicles. Defend against low-flying hostile aircraft

• MK19 40mm Grenade Launcher– Used to provide direct and indirect firing. Role is

similar to the M60E3 and M2.• AT-4

– Used against armored personnel carriers. Can be used to disable a battle tank (mobility kill) if struck properly.


• PQS Question 108.32 Describe the use and purpose of the following Night Observation Devices.

* AN/PVS-7C (night goggles)* AN/PVS-12A (M240B, M16, M14)* AN/PVS-20 (MK19, M2)

Reference: [c] Seabee Battle Skills Guide, Vol. 1

AN/PVS-7C

Night Vision Devices AN/PVS-7C (Night Goggles)

• AN/PVS-7C - Hand held or head mounted night vision system that enables walking, driving, weapon firing, short range surveillance, map reading and vehicle maintenance in both moonlight and starlight.

• Range - min 9.8”

AN/PVS-12A

• AN/PVS-12A (M240B, M16, M60, M14) – The AN/PVS-12A, Night Vision Individual Weapon Sight

System provides the infantry and support weapons with high performance observation, target acquisition and aiming capabilities during night operations. The Sight is capable of focusing on targets from 82 feet to infinity. The AN/PVS-12A is submersible, which permits the transportation of the AN/PVS-12A unprotected in two (2) atmospheres (66 feet) of seawater. The Sight is a high performance night vision system for nighttime target acquisition. The Sight uses a GEN III, 18 mm image intensifier tube configured in accordance with MIL-I-49428. Mounting hardware, which can easily be changed to other type mounts, are provided for attachment to the M16 and M14 Rifles.

AN/PVS-20

• AN/PVS-20 (MK19, M2) – The AN/PVS-20, Night Vision Individual Weapon

Sight System provides the infantry and support weapons with high performance observation, target acquisition and aiming capabilities during night operations. The Sight is capable of focusing on targets from 82 feet to infinity. The AN/PVS-20 can be used on the M2 .5 Cal. Machine Gun, and Mk38 Mod 0 25mm Machine Gun System. Mounting brackets and reticule cells are available for each type of weapon. The Sight may also be used as a tripod mounted observation device.

Classes of Fire

• PQS Question 108.33 Explain the various classes of fire:

* Grazing* Plunging* Overhead* Fixed* Traversing* Searching* Combine searching and traversing* Swinging traverse* Free

Reference: [e]Construction Battle Skills Guide, Book 1

Classes of Fire

• Grazing– Not less than 1m above and no higher than 68” above the ground. Can

exist for 700m over level or evenly sloping ground• Plunging

– Fire that strikes the ground from above at a considerable level. Beaten zone is considered the danger space.

• Overhead– Fire delivered over the heads of troops. Usually plunging fire overhead.

• Fixed– For targets requiring only one aiming point. Continuous as long as target

remains in the zone of fire• Traversing

– Distributed in width by changing the horizontal direction of the gun. Firing a burst each time the gun changes direction

• Searching– Distributed in depth by changing the elevation of the gun. Used against

deep targets, firing a burst each time elevation changes

Classes of Fire

• Combined searching and traversing– Distributed in width & depth by changing the elevation

direction of the gun.• Swinging traverse

– Delivered against targets to wide to cover the traversing hand wheel. Also used on targets moving so rapidly across the gunner’s front they cannot maintain effective fire using the traversing hand wheel . Cannot be fired from bipod or vehicles.

• Free– Delivered from the tripod mount against targets requiring

rapid and major changes in direction and elevation. Can also be used from a vehicle mount when the target cannot be covered adequately by aiming points. Cannot be fired from bipod mount.

seabeecombat warfare common core unit 108 weapons fundamentals navedtra 43904-c

Documents

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rules of weapons safety

weapon conditions reference

weapon conditions condition

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