SEABEE COMBAT WARFARE COMMON
CORE
108 WEAPONS FUNDAMENTALS
References
a. NAVEDTRA 14234
, Seabee Combat Handbook, Vol. 1
b. NAVEDTRA 14324
, Gunners Mate
c. Seabee Battle Skills Guide Vol.
d. NTRP 3-07.2.2
e. Construction Battle Skills Guide, Book 1
, All Hands 2005 Edition.
f.
TM-SW215-BC-MMO-010
, Operator’s and Maintenance Manual for
AN/PVS-12A, Night Vision, Crew Served Weapons
References
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
, Operator’s Manual Machine Gun, Cal. 50; Browning M2
Heavy Barrel Ch.1, sec, II Pg. 1-5
l.
FM 3-22.68
•
Treat Every Weapon as if it were loaded
•
Never point a weapon at any thing you do not intend to shoot
•
Keep your finger straight and off the trigger until you intend to fire
•
Keep the weapon on safe until you intend to fire.
PQS Question 108.1,
State the four rules of weapon
safety.
• Condition One - Magazine is inserted, a round must be in position to fire (chambered), the safety is on.
• Condition Two - Does Not Apply to weapons in the NCF.
• Condition Three - Magazine is inserted, chamber is empty, the action is closed and the safety is on.
• Condition Four - All ammo is removed, the chamber is empty, the action is closed and the safety is on.
PQS Question 108.2, Define the four weapon conditions:
PQS Question 108.3
, What weapons systems are in the NCF:
[ref. l, ch. 3; ref b, ch. 3]
• M16A3 SERVICE RIFLE
• M4A1 CARBINE
• M9 SERVICE PISTOL
• M500 12GA SHOTGUN
• M203 40MM GRENADE LAUNCHER
• M203A1 40MM GRENADE
LAUNCHER
• M240B MACHINE GUN
• M2HB .50 CAL BROWNING MACHINE
GUN
• MK19 MOD 3 40MM GRENADE
• MALFUNCTION - The failure of a weapon to function satisfactorily, usually because of excess friction caused by dirt, improper lubrication or carbon buildup.
• 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.
• STOPPAGE - Any interruption in the cycle of functioning caused by faulty action of the weapon or ammunition.
PQS Question 108.4, Define the following terms associated with the
M16A3 and the M9.
[ref. a, ch. 3]FEEDING
The feeding action places a round in the receiver just to the rear of the chamber.
PQS Question 108.5, State the eight steps of operation in a firing
cycle.
[ref. b, ch. 3]
CHAMBERING
• Chambering - Takes place as the moving bolt strips the round and forces it into the chamber.
LOCKING
• Locking - Holds the bolt in the forward position for a short period of time to prevent the loss of gas pressure.
FIRING
UNLOCKING
EXTRACTING
• Extracting - The process of pulling the empty case back out of the chamber. As the bolt moves rearward extraction occurs.
EJECTING
COCKING
• Cocking - The retraction of the firing mechanism against spring pressure so that there will be sufficient energy to fire the next cartridge.
• SEMI AUTOMATIC: A semiautomatic weapon unlocks, extracts, ejects, cocks and reloads automatically, however, the trigger must be pulled each time to fire a round.
• AUTOMATIC: A automatic weapon unlocks, extracts, ejects, cocks and reloads
automatically and will continue to fire automatically while the trigger is pulled until the ammunition source is exhausted.
PQS Question 108.6, Explain the differences between semi-automatic
& automatic operation.
• Trajectory- The flight path of the bullet from the weapon to the target.
• Breech- The opening in the barrel closest to the operator.
• Bore- The hole in the center line of the barrel (in which the bullet travels)
• Chamber- The enlarged portion of the barrel that houses the cartridge for firing.
• Muzzle- The opening in the barrel farthest from the operator.
PQS QUESTION 108.7, Define the following terms:
Define the following terms(cont’d):
• Muzzle Velocity-The speed at which the bullet leaves the muzzle.
• Maximum Range- The Greatest distance the round will travle
• Maximum Effective Range- The greatest distance at which a weapon may be expected to fire accurately to inflict damage or casualties.
• Orange or red [ref. a, ch. 3]
• Tracer
• Violet [ref. a, ch. 3]
• Blank
• Black [ref. a, ch. 13]
• Armor Piercing
• Aluminum [ref. a, ch. 13]
• Incendiary • Green [ref. a, ch. 3]
• Standard Ball
PQS QUESTION 108.8, Discuss small arms ammunition color codes
and state the purpose of each:
•
M9 Service Pistol
•
M16A3 Rifle
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 Characteristics
•
Semi-automatic
•
Magazine fed
•
Recoil Operated
•
Double Action or single action firing pistol
•
Current issue sidearm
M9 Capabilities/Characteristics
• Length - 8.54 in
• Weight - 2.12 lb
• Weight fully loaded (15 rnd mag) - 2.54 lb
• Magazine capacity - 15 rounds
• Muzzle velocity - 1230/fps
• Max range - 1800 m
• Max effective range - 50 m
M9 SAFETY FEATURES
•
The M9 pistol has only ONE external/manual safety.
•
Ambidextrous Manual Safety/Decocking lever
•
However, it has THREE SAFETY FEATURES.
•
Ambidextrous Manual Safety/Decocking lever
•
Half Cock Safety notch
M9
•
Purpose- Self Defense
•
Tactical Employment- Individual, hand-held weapon intended for
use in close combat
M16 DESCRIPTION
• Lightweight
• Gas operated
• Air cooled
• Magazine fed
• Shoulder fired
• Semi-automatic or fully automatic
M16 Selector Lever
• Safe position - Rifle will not fire.
• Semi - position - The trigger must be pulled each shot.
• Automatic position - Rifle will continue to fire as long as the trigger is held back or until the ammunition source is exhausted/expended.
M16 Capabilities/Characteristics
• Length w/flash suppressor -39 in
• Length of barrel w/flash suppressor - 21 in
• Weight - 7.8 lbs
• Weight fully loaded (30 rnd mag) - 8.79 lbs
• Magazine capacity - 20/30 rounds
• Muzzle velocity - 3100/fps
• Max range - 3534 m
M16 Rates of Fire
• Sustained - 12 to 15 rounds per minute
• Rapid - 150 to 200 rounds per minute
M16 AMMUNITION TYPES
• 5.56mm Ball - Standard round
• 5.56mm Tracer - Used to mark targets or cause incendiary effects
• 5.56mm Blank - Training round
M16
•
Purpose:
˗ Self-defense
Tactical Employment:
a. Fragmentation b. Illuminating c. Chemical d. Incendiary e. Smoke
f. Practice/training g. Concussion
PQS QUESTION 108.11, Describe and discuss the following types of
grenades:
[ref. a, ch. 12; ref. d, ch. 13]FRAGMENTING
M67 Fragmentation Grenade:• Grenades designed to inflict personnel casualties and damage to light equipment by projecting high velocity fragments from the detonated grenade case.
ILLUMINATING
• Used to illuminate terrain in night time operations.
• Once pin is pulled, GRENADE MUST BE THROWN!
• Grenades used mainly to light up the terrain in night operations.
• The Mk 1 is the only illuminating grenade currently available.
CHEMICAL
• Used for incendiary, screening, signaling, training and riot control purposes
• M25A2 CS Riot grenade
• 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.
INCENDIARY
• AN-M14 incendiary Thermite is used to ignite combustible materials and to destroy all types of equipment.
• This TH grenade is cylindrical in shape and weighs 32 ounces (900 grams).
• Contains filler of 26.5 ounces (751 grams) of Thermite mixture.
• It uses an igniting delay fuse that sets fire to the Thermite.
SMOKE
• Grenades that are cylindrical in shape and weigh about 27 ounces (765 grams).
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.
• Hand grenade safety precautions must be observed by everyone who handles and/or throws any and all types, and by other persons who may be within the grenade's danger area.
• Anyone within the danger area of a casualty-producing grenade (about 55 yards or 50 meters) must wear a steel helmet.
• When the safety pin is pulled, the safety lever or arming device should be held down firmly until it is thrown.
PQS QUESTION 108.12, Discuss hand grenade safety procedures.
HAND GRENADE SAFETY
• All personnel handling casualty producing grenades must wear proper protection.
• Never attempt to defuze hand grenades.
• Do not remove the safety pin until ready to throw.
• Range / Coverage: When detonated, the M18A1 mine will project steel spheres over a 60 degree fan-shaped pattern approximately 6 feet (1.8 meters) high and 164 feet
(50 meters) wide to an optimum effective range of 55 yards (50 meters).
• These steel fragments are moderately effective up to a range of approximately 110 yards (100 meters) and can travel up to 275 yards (250 meters).
PQS QUESTION 108.13, Discuss the characteristics and purpose
of the Claymore mine.
[ref. a, ch. 12]CLAYMORE MINE
• Placement: This mine should be positioned so as to Afford all friendly personnel, within 110 yards (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.
CLAYMORE MINE
• 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.
The following items apply to the 7.62mm M240B
machine gun:
• Gas operated
• Air Cooled
• Fully Automatic
• Metalic Link Belt Fed
• Ammunition: 7.62x51mm NATO
• Length: 49 inches
• Weight: 27.1 pounds
M240B
PQS QUESTION 108.14, Describe the characteristics of the machine
gun.
[ref. l ch.3]1. Cover raised method:
a. Place the safety on the F (fire) position
b. Pull the cocking handle to the rear, locking the bolt to the rear position.
c. Return the cocking handle to the forward position, and place the safety in the S (safe) d. position.
e. Raise the cover; and ensure that the feed tray, receiver, and chamber are clear.
f. Ensure that the assistant gunner places the first round of the belt in the feedtray groove, g. with the open side of the double links facing down. (Ensure that the cartridge retainer pawl h. holds the ammunition link on the feed tray)
i. Close the cover. The gun is now loaded.
M240B
PQS QUESTION 108.15, Discuss loading/unloading procedures.
[ref.M240B
Discuss loading/unloading procedures(cont’d)
2. Cover closed method:
a. Place the safety in the F (fire) position.
b. Direct your assistant gunner to push the first round of a belt of ammunition (open side of links down) into the feed tray until a distinct click is heard.
c. Pull the cocking handle to the rear, and return it to its forward position. The gun is now loaded.
M240B
Discuss loading/unloading procedures(cont’d)
Unloading:
1. Ensure weapon is on Safe
2. Pull and hold charging handle to the rear (palm up) 3. Head down, reach up and open top cover
4. Sweep feed tray with non firing hand
5. Physically check bolt face and chamber with non firing hand 6. Visually inspect clear
a. Proper employment [ref. l ch.3]
• Machine guns, though powerful weapons, do not stand alone. They are most effectively employed in concert with other weapons in an attempt to achieve a
synergistic effect where the fires of one weapon compliment or augment the fires of another.
• Basis for Final Protective Fire (FPF) in the defensive fire plan.
• Whenever grazing fire can be attained, the M240B should be assigned the mission of firing an FPL.
• The guns should generally be positioned on the flanks with interlocking FPLs and sectors of fire across the unit’s front.
• All dead space in an FPL should be covered by other weapons systems.
• FIG – Flanking, Interlocking, Grazing
M240B
PQS QUESTION 108.16, State the following capabilities/
nomenclature:
M240B
State the following capabilities/ nomenclature:
b. FPL/PDF [ref. l ch.5
a. Mainly employed as an FPL weapon but can also serve as a PDF weapon
c. Maximum effective range [ref. l ch.3]
a. 1800 meters area on a tripod with no T&E b. 1100 meters area on a tripod with T&E
c. 800 meters point target on a tripod with T&E d. 800 meters area target using the Bipod
e. 600 meters point target using the Bipod
d. Safeties M240B [ref. l ch.3]
M240B
State the following capabilities/ nomenclature:
d. Ammunition types [ref. l ch.3]
• Ball cartridges: are used against light targets such as houses and personnel, and
• during training.
• Armor-piercing cartridges: are used against lightly armored targets where armorpiercing
• effects are desired.
• Armor-piercing incendiary cartridges: are used for desired armor piercing effects
• combined with fire-producing (incendiary) effects.
• Tracer cartridges: are used for observation of fire, incendiary effects, signaling,
• and during training.
• Dummy cartridges: are used during training.
• Blank cartridges: are used with a Blank Firing Attachment (BFA) during training when
M240B
State the following capabilities/ nomenclature:
e. Rates of fire [ref. l ch.3]
• Sustained: 100 rpm
NOTE: The weapon can fire this rate of fire (with six to nine round bursts) for 10 minutes before the barrel must be changed.
• Rapid: 200 rpm
NOTE: Can be delivered for two minutes before barrel must be changed.
• Cyclic: 650 to 950 rpm
•
TYPES OF MOUNTS [ref. I ch.3]:
1. Ground mounts:
• M122 Tripod w/ MK105 Gun mount
2. Vehicle Mounts:
• MK 97 Gun Mount
• MK 175 Mount
M240B
•
Squad leader:
carries
the binoculars and compass.•
Team leader:
carries the tripod and one box of ammunition.•
Gunner:
carries the machine gun with one bandoleer of ammunition.•
Ammunition bearer:
carries the spare barrel case, flex-mount with T&E mechanism, and one box of ammunition.M240B
PQS Question 108.17
, Name the members of a gun team and state what they are responsible for carrying into a combat situation. [ref. a, p. 1-17]MK19
PQS QUESTION 108.18, Describe the characteristics of 40mm
machine gun. [ref. j]
• Blow back Operated
• Air Cooled
• Fully Automatic, Open bolt fired
• Disintegrating Metalic Link Belt Fed
• Ammunition: 40mm Grenades
• Length: 43.1 inches
• Weight: 75.6 pounds
MK19
PQS QUESTION 108.19, Discuss loading/unloading procedures.
[ref. j]
1. Loading:
• Insert the first round, female link first.
• Push the round across the first pawl until it clicks and move the feed slide assembly to the left.
• Close the feed cover. If it does not close easily, manipulate the feed slide assembly.
• Grasp the charger handles and press the charger handle locks up and in.
• Rotate the charger handles down and pull them to the rear.
• Press the locks and push the charger handles forward and up to the original position.
• Place the safety on F and press the trigger, the bolt will spring forward, loading the first round on to the face of the bolt.
• Pull the charger handles to the rear which places the bolt and round in position to fire.
• Press the charger handle locks and return the handles to the forward and up position.
MK19
Discuss loading/unloading procedures(cont’d).
2. Clearing: Observe the following procedures:
• Put the weapon on S and keep it pointed down range.
• Charge the weapon and leave the charger handles to the rear and down.
• DO NOT open the cover
• Insert a length of cleaning rod through the right hand receiver rail as close to the face of the bolt as possible.
• Push down on the casing (the round may be live or spent) forcing it off the face of the bolt and out the bottom of the gun.
• The squad leader/assistant gunner should catch the round as it falls out.
MK19
Discuss loading/unloading procedures(cont’d).
3. Unloading.
‒ To unload the gun:
• Open the cover
• Reach beneath the feeder
• Press the primary and secondary positioning pawls
MK19
PQS QUESTION 108.20
, State the following: capabilities/nomenclature:
a. Proper employment [ref m, ch. 6, sec. I] b. FPL/PDF [ref m, ch. 6, sec. I]
c. Arming range [ref. j]
d. Maximum effective range (area target) [ref. j] e. Maximum effective range (point target)] [ref. j] f. Rate of fire [ref. j]
g. Safety [ref. j]
MK19
Proper employment [ref m, ch. 6, sec. I]
Effect against armor:
The MK-19, with its high explosive dual-purpose round, is effective against light armor. It will penetrate 2 inches of homogeneous steel with 0 degrees obliquity out to 2,200 meters. It should be noted, however, that it is difficult to effectively engage moving vehicles with the MK-19 because its 40mm ammunition has a high angle of trajectory, slow time of flight, and can suffer adverse aerodynamics (drift), that becomes especially pronounced at ranges greater than 1,000 meters.
Effect against personnel:
The MK-19’s high explosive or high explosive, dual-purpose round make it very effective against personnel, with an effective casualty radius of 15 meters.
MK19
FPL/PDF [ref m, ch. 6, sec. I]
In the defense:
The MK-19, with its high trajectory, is not suitable for an FPL in the defense and
should normally be assigned a PDF to cover an avenue of approach, an obstacle, a defile, a choke point, or dead space in the FPL of a flatter trajectory weapon.
MK19
Arming range [ref. j]
• HE Rounds: M383 and M384. Arming distance: 18-30 meters.
• HEDP Round: M430:
Arming distance: 18-40 meters.
• Practice Rounds:
Arming Distance: 18-30 meters (Upon impact, the M918 produces a flash, smoke, and a loud report to simulate the explosion of the HEDP round).
MK19
Maximum/Maximum effective range (area/point target) [ref. j]
• Maximum effective range:
• Point target ... 1,500 meters
• Area target ... 2,212 meters
• Maximum Range:
MK19
Rate of fire [ref. j]
Rates of fire:
Sustained ... 40 rounds per minute Rapid ... 60 rounds per minute Cyclic ... 325-375 rounds per minute
MK19
Safety [ref. j]
MK19
Ammunition types [ref. j]
• High Explosive. High explosive (HE) projectiles are used for fragmentation effect against light materials and fortifications and personnel. The casings are olive drab with a yellow ogive and yellow markings.
• High Explosive Dual Purpose. High explosive dual purpose (HEDP) ammunition has a high explosive projectile with an internally shaped charge capable of armor penetration as well as fragmentation effect. They are used against lightly armored vehicles, medium and light materials and fortifications, and personnel. The M430 HEDP round (DODAC1310-B542) is the standard round for the MK-19. The casings are olive drab with a yellow ogive and yellow markings.
• Practice. Practice rounds have a solid, nonexplosive projectile. One type contains a flash charge inside to simulate explosion upon impact. They are used in range gunnery practice. The M918 is blue with a blue ogive and brown band and black markings. The M385 is blue with a blue ogive and black markings.
M2HB
PQS QUESTION 108.21
, Describe the characteristics of the M2 machine gun.
[ref. k, ch. I, sec II, p. 1-5]
• Recoil Operated
• Air Cooled
• Disintegrating Metalic Link Belt Fed
• Ammunition: .50 Caliber BMG (12.7x99mm NATO)
• Length: 65 inches Total (Barrel length is 45 inches)
• Weight: 84 Pounds
• Receiver 60 pounds
• Barrel 24 pounds
M2HB
PQS QUESTION 108.22, Discuss loading / unloading procedures. .
[ref. k, ch. I, sec. II, p. 1-5]
1. Loading:
• Ensure weapon is clear and in Single Shot Mode
• Ensure bolt is forward and top cover is closed
• A-gunner/Squad leader will insert the double loop end of the ammuntion belt into the feed way.
• Gunner will quickly/vigorously pull the charging handle all the way to the rear locking the bolt back
• Gunner will return the charging handle fully forward
• Release the bolt using the bolt release
• Weapon is now at HALF LOAD
• Gunner will again charge the weapon and return the charging handle fully forward
• Gunner will again Release the bolt
• Weapon is now at FULL LOAD.
M2HB
2. Unloading:• Place weapon in Single Shot Mode
• With head down, grasp charging handle and pull fully to the rear and hold
• A-gunner/Squad leader will retrieve the ejected live round from under the gun
• Gunner reach up and open top cover
• Sweep remaining Ammo/Ammo Links from the feed way
• Blindly feel the chamber and bolt face (T-Slot)
• If a round is present on the bolt face
• Gunner will remove the round by pulling the charging handle an additional 1/16 an inch to the rear and pushing the round up and out of the T-Slot (Bolt Face) from the bottom of the gun.
M2HB
PQS QUESTION 108.23, State the following capabilities /
nomenclature:
a. Proper employment [ref m, ch. 6, sec. I] b. FPL/PDF [ref m, ch. 6, sec. I]
c. Maximum effective range (area target) [ref. j] d. Maximum effective range (point target)] [ref. j] e. Rate of fire [ref. j]
f. Safety [ref. j]
M2HB
PROPER EMPLOYMENT
• The M2HB .50 Caliber Machine Gun can be effectively employed on a PDF or an FPL
• The M2HB is employed as a ground mounted weapon using the M3 Tripod, pintle and Traversing and Elevating Mechanism
• The M2HB is also employed on a variety of vehicles using the MK 93 MOD2 or MK93 MOD 4 gun mount.
M2HB
PDF Employment
Effect against armor. The M2 .50 cal, when firing the sabot light armor penetrator (SLAP) round, is highly effective against light armor targets out to ranges up to 1,500 meters. At that range the SLAP round will penetrate 3/4 of an inch of steel armor at 0 degrees obliquity. The M2 .50 cal can be effectively employed against moving vehicles. Making it a very effective weapon on a PDF such as an ECP or Avenue of Approach.
M2HB
FPL Employment
Effect against personnel. The M2 .50 cal is also an effective weapon against personnel because of its high volume of fire and 700 meters of grazing fire. These characteristics make the M2 .50 cal well suited for the assignment of an FPL in the defense against infantry attack.
M2HB
Ranges
• Maximum Range:
• 7,400 meters (approximate)
• Maximum effective:
• 1,830 meters
• Grazing fire:
M2HB
Direction Of Feed
The M2HB .50 Caliber machine gun can either be Right hand Feed or Left hand Feed. This refers to the direction in which the belt of Ammunition is fed into the gun. In most applications they are only Right hand feed when used in a Dual M2HB set up (One gun fed
from the left, one fed from the right).
All of NMCB 11’s M2HB’s are LEFT HAND FEED
It is important to be aware of this so the operator ensures that the bolt switch is placed in the correct position.
M2HB
Rates of Fire
• Sustained:
• 40 rounds or less per minute
• Rapid:
• More than 40 rounds per minute
• Cyclic:
M2HB
Headspace and Timing
• Headspace:
• Headspace is the distance between the face of the bolt and the base of the cartridge case fully seated in the chamber.
• Improper headspace will lead to improper operation of the machine gun and frequently results in injury to personnel and damage to or destruction of the machine gun.
• Headspace is to be checked after each barrel change, watch turnover, and pre fire inspections of the weapon
M2HB
Headspace and Timing
• Timing:
• Timing is the adjustment of the weapon so that firing takes place when the recoiling parts are between .020 and .116 inches out of battery to prevent contact between the front end of the barrel extension and the trunnion block.
• Timing is correctly set when the recoiling parts are locked together, firing takes place just before the parts are in battery (fully forward), and when the gun fires on the FIRE gage and does not fire on the NO FIRE gage.
• Timing must be checked and/or set each time headspace is set, or whenever timing is questionable.
M2HB
Headspace and Timing
• Setting Headspace:
• Ensure weapon is cocked and bolt is forward
• Retract Bolt Until The lug on the barrel locking spring is aligned with the 3/8-inch hole in the right side of the receiver.
• Slide barrel into the receiver and screw it all the way into the barrel extensions, note the audible clicks heard by the barrel locking lug.
• Unscrew the barrel two clicks.
• Return bolt/recoiling parts fully forward.
• Pull back on the charging handle until there is a small gap between the front of the barrel extension and the trunion block (feed way) as per the TM.
• Insert NO GO end of headspace gauge into the T-Slot (space between the bolt face and the chamber) the gauge should not fit.
• Attempt to insert the GO end of the gauge into the T-Slot, if the GO gauge does not fit.
M2HB
Headspace and Timing(cont’d)
• Setting Headspace:
• Again Retract Bolt Until The lug on the barrel locking spring is aligned with the 3/8-inch hole in the right side of the reciever.
• Unscrew the barrel one click
M2HB
Headspace and Timing
• Setting Timing:
• After setting Headspace Begin setting timing.
• Raise Extractor Delinker.
• Retract bolt/recoiling parts so that the barrel extension is approximately ¼ of an inch from the trunnion block.
• Insert NO FIRE gauge into slot placing the beveled edge of the gauge onto the barrel notches.
• Slowly allow the recoiling parts to close on the gauge.
• Press firmly on the trigger, the weapon should not fire.
• If weapon does not fire, retract the recoiling parts and remove the NO FIRE gauge.
• Insert the FIRE gauge into the slot the same as the NO FIRE was inserted.
• Press the trigger, weapon should fire.
M203
PQS QUESTION 108.25, State the following
capabilities/nomenclature: [ref. i]
a. Proper employment b. Ammunition type
c. Maximum effective range (area target) d. Maximum effective range (point target) e. Maximum range
M203
Description/Proper Employment
• Description:
• Shoulder Fired (attached to either an M16 or M4)
• Air Cooled
• Breach Loaded
• Manually operated/Pump Action
• Single Shot 40mm Grenade Launcer
The M203 is employed as a single shot shoulder fired Indirect Fire Weapon. It is employed by the squads Grenadier to cover dead space in the fire plan and to support the squads sector
M203
Ammunition Type
• HE/High Exploxive:
• The HE round has gold markings, and a yellow ogive. It arms between 14 and 27 meters, produces a ground burst that has a kill radius of 5 meters.
• HEDP High Explosive Dual Purpose:
• The HEDP round has a gold ogive (head of the round). It penetrates 2 inches when fired straight at steel armor at 150 meters or less, or, at a point target, arms between 14 and 27 meters, has a kill radius of 5 meters.
• Star Cluster:
• White Star Cluster Round. The round is used for illumination or signals. The individual stars burn for about 7 seconds during free fall.
• Star Parachute:
• Star Parachute Round is used for illumination and signals the parachute candle burns for about 40 seconds.
M203
Ammunition Type
• Ground Marker/Smoke:
• It is used for aerial identification and for marking the locations. It arms between 15 and 45 meters. The color of the ogive indicates the color of the smoke
• Practice Round:
• Used for practice it produces a yellow or orange signature on impact, arms between 14 and 27 meters, and has a danger radius of 20 meters.
• Buckshot Round:
• Though it is a multipurpose round, it is most effective in thick vegetated areas or for room clearing. Inside, it has 20 metal pellets, each weighing 24 grains, with a muzzle velocity of 269 meters per second.
M203
Ranges
• Maximum Range:
• 400m
• Max effective range (area target):
• 350m
• Max effective range (point target):
M500
PQS QUESTION 108.27, Describe the characteristics of the M500
12-gauge shotgun. [ref. h, p. R3-19]
• Air Cooled
• Manually Operated
• Pump Action
• Tubular Magazine Fed
• 12 Guage
M500
PQS QUESTION 108.28, Discuss loading/unloading procedures.
[ref. h, p. R3-20]
1. Loading
• Ensure weapon is clear, bolt forward and on safe
• With the bottom of the weapon pointing up
• Insert rounds into the tubular magazine plastic end first one at a time
• After you have loaded the magazine
• Roll the weapon over
• Press the action bar lock and retract the slide
• Once a round has been pushed onto the elevator
• Firmly push the slide forward locking the bolt into battery
M500
2. Unloading
• Ensure weapon is on safe.
• Roll weapon over so the bottom is pointing up.
• Press the cartridge stop into the side of the receiver allowing the round to slide out of the receiver.
• Remover round from the bottom of the weapon.
• Repeat these steps until the magazine tube is empty.
• Roll the weapon back over.
• Push in on the action bar lock.
• Slowly pull the slide back opening the chamber.
• Catch live round as it is coming out of the weapon.
M500
PQS QUESTION 108.29, State the following
capabilities/nomenclature: [ref. h, p. R3-20]
• Length
• 39 inches (approximately)
• Safeties
• The M500 Has one safety located on the top of the receiver (Tang Safety)
• Ammunition Types
• 12 Guage
• The navy uses two types of ammunition for the M500 ‒ Slugs
PQS QUESTION 108.30, Describe the use and purpose of the
range card as it relates to each weapon system. [ref. n, ch. 4, ref i]
• A range card is a rough sketch or drawing which serves as both a record of firing data and a document for defensive fire planning.
• One copy remains at the gun position as a record of firing data. The gunner uses the card to recall the data to fire on predetermined targets and as an aid in estimating ranges to other targets during good visibility.
• The other copy is sent to the next higher headquarters (usually the company), who use it to organize the defense and prepare a fire plan sketch.
Range Card Contents
• The machine gun number
• Unit designation
• Date and time the range card was prepared
• The machine gun position
• A magnetic North arrow
• The left and right lateral limits
• The assigned FPL or PDF
• Magnetic azimuth of the machine gun to a prominent terrain feature
• Dead space
• Areas signifying grazing fires
• Specified targets numbered in sequence with their direction in mils, elevation in mils, and range in meters.
When a defensive fire plan is devised, leadership will take into account the strong suits of all the weapon systems at their disposal, terrain and amount of equipment. Using this information and the information and range cards gathered from the individual companies
and squads a defensive fire plan can be put together using interlocking fields of fire.
PQS Question 108.31, Discuss the integration of the weapons systems into an overall defensive fire plan. [ref. n, ch. 4, ref i]
Classes of Fire
PQS Question108.33, Explain the various class of fire:
[ref. e, pp. 3-30 thru 3-31]
• Grazing Fire - Fire approximately parallel to the ground where the center of the cone of fire does not rise above 1 meter. When firing over level or uniformly sloping terrain, the maximum extent of grazing fire obtainable for the M240B is approximately 600 meters. The maximum extent of grazing fire obtainable for the M2 .50 cal is
approximately 700 meters.
• Plunging Fire - Fire in which the angle of fall of the rounds, with reference to the slope of the ground, is such that the danger space is practically confined to the beaten zone and the length of the beaten zone is materially shortened.
• Frontal - The long axis of the beaten zone is at a right angle to the long axis of the target.
• Oblique Fire - The long axis of the beaten zone is at an angle, but not a right angle, to the long axis of the target.
• Enfilade Fire - The long axis of the beaten zone coincides or nearly coincides with the long axis of the target. This class of fire is either frontal or flanking and is the most desirable class of fire with respect to the target, because it makes maximum use of the beaten zone.
• Fixed Fire - Fire delivered on a point target. Little or no manipulation is required. After the initial burst the gunner will follow any change or movement of the target without command.
• Traversing Fire - Fire distributed against a wide target requiring successive changes in the direction (left and right) of the gun.
• Searching Fire - Fire distributed in depth by successive changes in the elevation of the gun.
• Traversing and Searching Fire - Fire delivered both in width and depth by changes in direction and elevation.
