12.7 Mm AAMG Past Paper PDF

**[\ ]** **[12.7 AAMG]** 1. 12.7 mm AAMG is used and against **[low-flying aerial targets]**, such as **[aircraft]**, **[parachutists]** illuminating shells. If necessary, it can be used to destroy **[ground targets]**, such as **[armoured cars]**, **[infantrymen]** and **[str...

**[\ ]** **[12.7 AAMG]** 1. 12.7 mm AAMG is used and against **[low-flying aerial targets]**, such as **[aircraft]**, **[parachutists]** illuminating shells. If necessary, it can be used to destroy **[ground targets]**, such as **[armoured cars]**, **[infantrymen]** and **[strongpoints]**. 2. **[Characteristics]**. a. Muzzle Velocity. 840 metres per second. b. Effective Firing Range 1. Aircraft. 1600 metres. 2. Armoured Targets. 800 metres 3. Strong point. 1500 metres 4. Enemy Infantry. 3300 metres 3. Maximum Flight Distance for Bullet. **7000 m** at **45 angle** of fire. 4. Effective Firing Height. **1000 metres** 5. Type of Cartridges. c. **[Armour Piercing Incendiary (API)]** d. **[Armour Piercing Incendiary Tracer (APIT).]** 6. Armour Penetration. e. **Steel. 20 mm** at 100 metres distance. f. **Brick Wall. 250 mm** at 100 metres distance. 7. Rate of Fire. **[560-600]** rounds per minutes. 8. Capacity of **Ammunition** Box. **[70 rounds with linked belt]**. 9. Structure. g. Cal **12.7** h. Rilfings **8 Rt hand** i. Traverse **360 degrees** j. Elevation **30-80 degrees** 10. Weight 0 k. Total Weight. **84 kg**. l. Weight of Gun Body. **34 kg** m. Weight of Gun Mount. **17 kg** n. Weight of Support. **33 kg** o. Weight of Anti-Aircraft Sighting Equipment. **4 kg**. p. Weight of Shoulder Stock. **3 kg**. q. Weight of Ammunition Box. **13.62 kg** (including **70 rounds** of cartridges and linked belt). 11. The 12.7 mm AAMG consists of the r. barrel assembly, s. receiver, t. bolt assembly, u. feed mechanism v. trigger mechanism, w. gun mount, x. anti-aircraft sighting equipment, y. ammunition box, z. shoulder stock a. support. 12. Use of brl assy is to give **[direction]** to the bullet and to **[impart rotation]** to the projectile to achieve a steady flight 13. **[Brl Assy]**. b. The important parts on the barrel, are, **muzzle brake** and **gas regulator**. c. The muzzle brake, threaded on the barrel reduces the recoil by the impulse of powder gas to make the gun steady during firing. d. The gas regulator regulates the **[volume]** of **[powder gas]** which works on the **[piston]**, thus achieving automatic operation. The regulator has **[three gas ports]** of different diameters: **[3 mm, 3.5 mm and 4 mm]**. e. Usually it is set at **[3.5 mm]**. f. In extreme **[cold weather]** or during combat when the ports are partially clogged and there is no time to clean them, it is set at **[4 mm]**. g. In extreme **hot weather** or when the recoil strength of the machine gun is too great, it is set at **[3 mm]**. h. **Receiver** connects together the **barrel assembly**, **bolt assembly** and **trigger mechanism** to provide room for movement of the operating parts and to guarantee the locking of the gun. **[Receiver]** 14. **[Bolt Assembly]**. i. Use. It is used for 5. Loading 6. locking, 7. firing, 8. extracting 9. ejecting. j. Structure. It is composed of the **[bolt slide]** and **[bolt body]**. 15. **[Feed Mechanism]** is used to move **[cartridges]** to the **[feeding position]** so as to ensure **[automatic]** firing. k. It is composed of the 10. feed mechanism base, 11. feed mechanism cover (fig 6) 12. feed arm group 16. **[Trigger Mechanism]**. It works with the **[bolt assembly]**, and aids in firing the machine gun. 17. **[Gun Mount]**. l. **[Sighting Mechanism]**. It is used to enable the gun to **[aim]** at targets within **traversing and elevating limits**. 13. The weapon has a fixed TE of **[9.2 mils]**. 14. If gun is given the **9.2 mils** superelevation, targets between **[200 metres - 1600 metres]** can be engaged. 15. For alignment of AA sight, ground sight and the axis of bore the object be at **[900 metres]** 16. The **eff rg** of wpn is ** m**. m. **[Locking Mechanism for Elevation and Traverse]**. It is used to **fix** the gun body in elevation and traverse. n. **[Fine Sighting Mechanism]**. It serves to conduct **[accurate sighting]** both in **elevation** and **traverse** when the ground sight is used. o. **[Loading Mechanism]**. It serves to place the **[first cartridge]** in the position to be fired, by pulling the bolt slide frame backward, thus unlocking the bolt body and feeding the first cartridge into the feed slot. 18. **[AA Sighting Eqpt]** sets the course of **[serial targets]** and provides near accurate aim against **[enemy aircraft]**. It consists of p. front and rear AA sights q. course sight r. connecting rod s. mid-base t. ruler for computing the range and foreshortening. u. **[Rear sight leaf]** inclines to the **[left]** about **[2°33\']** for **[automatic modification]** of the constant deviation at different ranges. On it are the range graduations **[0-33]** (**[0-3300 metres]**). v. Interval between two holes is **[8mm]**. w. Distance between rear sight hole and central hole on front sight is\ **[340 mm]**. x. The angle b/w 2 aiming holes from rear sight **[0-23 mils]**. y. **Central hole** is always in agreement with **axis of the bore** i.e. it shall aim at the **[future posn]** of the tgt. z. **[Front Sight]**. 17. For a rg of 100m, the deflection of **1mm** at sight will cause a deflection of **9cm** at the tgt. 18. To set a TE of **[9.2 mils]**, at a rg of **[900m]**, the sight is placed at **[posn 9]** on the scale of computing ruler. a. The **[front AA sight]** has **[20 aiming holes]**, each of which is to be used in accordance with the target speed, range and foreshortening of the target object. b. To avoid mistakes, on the holes are **[small teeth]** which are equal in double number with the number of the holes. c. The **[hole]** in the **[centre]** is used in firing against **[diving aircraft]** and for **[adjustment]**. d. An **[aiming hole table]** is attached on the **[front sight]**. e. The front AA sight is connected with the course sight by the **[connecting rod]** and is fixed by the **[locking handle]**. Turning of the handle makes the course sight turn simultaneously with the front AA sight by action of the **[gear]**, **[gear ring]** and **[connecting rod]**, thus ensuring that **[ratios of the aiming holes]** remain parallel with the **[course line]**. f. Therefore, in mounting the AA sighting equipment, be sure to make the **[cut lines]** meet. g. The **[course sight]** serves to keep aiming holes constantly parallel to the course of enemy aircraft. For this purpose, an **[aircraft model]** is attached on the line of the target course. h. The rear AA sight works together with the front AA sight to **[aim]** the gun at the target. If the screw is loosened, the aiming holes can be moved vertically or horizontally to modify the aim. i. The rear sight is fixed on the frame by the **[locking plate]** and a **[wing nut]**. **[STRIPPING]** 19. The disassembly and assembly of the machine gun is carried out for (**CLIC)** j. Cleaning k. Lubrication l. Inspection m. Correction of malfunctions 20. **[Disassy]**. n. Removing the back plate gp o. Removing the trigger mech frame p. Removing the feed mech q. Removing the bolt assy r. Removing the gas regulator s. Removing the barrel 21. **[Removing the back plate group]** t. Fix the gun body in **level** position u. Unscrew the trunnion locking nuts by **one or two threads**, v. Clear the piston tube from the barrel by pulling the piston tube forward and turning it right. w. Pull out the gun body **connecting bolt** and punch out the pin. x. Hammer down the backplate group with a wooden hammer while holding the backplate group 22. **[Removing the Trigger Mechanism Frame]**. Hold the **connecting lugs** on the **trigger mechanism** frame with both hands. Press the **rear-end of the receiver** by the thumbs and pull the frame out rearward. 23. **[Removing the Feed Mechanism]**. y. Pull out the **split pin** and remove the nut with a wrench. z. Pull out the connecting bolt and then remove the feed mechanism from the receiver. a. Separate the feed mechanism base. b. From the cover, pull out the pin of the **long feed arm**, wrench off the nut and remove the long feed arm. c. Pull the long feed arm axle out and pour **the coned axle** of the short feed arm out by turning the feed mechanism cover upside down. Then remove the short feed arm and bolt feed slide from the **right side**. 24. **[Removing the Bolt Assembly]** d. Press down the rear part of the receiver slightly and pull the cocking handle backward until the bolt body is out of the receiver. e. Then hold the rear part of the bolt assembly, continue to pull it until the piston level is laid on the gun mount. f. Gently leave the receiver, grip the front part of the piston tube and remove the bolt assembly from the gun body. g. Separate the bolt body from the bolt slide. Remove the extractor along with its spring and firing pin head. h. Punch out the extractor pin. Hold the bolt body, press and turn the extractor allowing its side to face upward and remove the extractor and its spring. i. Then punch out the firing pin head limiting pin, and take out the pin head. j. Remove the return spring and piston. k. Pull the split pin, punch out the connecting sleeve fixing pin, grip the piston tube and press it downward. l. Engage the wrench on the piston lever and wrench off the bolt slide. m. Then remove the wrench, gently leave the piston tube and remove the return spring and piston lever. 25. **[Removing the Gas Regulator]**. Pull out the split pin, unfasten the nut and remove the gas regulator by moving it backward. 26. [**Removing the Barrel** (Carried out in Replacement)]. Remove the locking bolt nut, pull out the locking bolt and remove the barrel. **[ASSEMBLING]** 27. The assembly is carried out in the **[reverse]** order of disassembly. 28. To Replace the Barrel. Insert the rear end of the barrel into the receiver up to the proper position, place the locking bolt and tighten the nut. 29. To Replace the Gas Regulator. Place the front part of the gas regulator in the gas block, with the desired marking line of the gas port aligned with the setting line on the gas block and fix the nut. Then insert the split pin. 30. To Assemble the Bolt Assembly n. Press the piston tube down, engage the wrench on the connecting sleeve of the bolt slide on the piston lever and insert the fixing pin o. To Replace the Extractor and Firing Pin Head. Place the firing pin head (with the even face upward) into the firing pin head hole of the bolt body and punch in the limiting pin. Hold the bolt body and insert the extractor spring into the groove hold. Then place the extractor in the groove with its side facing upward. Depress the front part of the extractor with the index finger and turn it to its proper position with the thumb. Then place the extractor fixing pin. p. To Replace Bolt Assembly. Engage the bolt body with the bolt slide, (with the rear part of the firing pin into the firing pin base, and the shaped part into the shaped groove). Hold the rear position of the bolt slide with the right hand and grip the piston tube while turning the protuberance on the piston tube rightward and lay the piston lever on the gun mouth. Then depress the rear portion of the receiver, insert the guiding keys on the bolt slide into the guiding grooves on the receiver, and push the bolt slide forward until the piston enters into the gas regulator. 31. To Replace the Feed Mechanism. Insert the bolt slide into the slide groove from right, place the short feed arm into the feed arm notch from the same side, put the short feed aim coned axle in the axle hole, insert the long feed arm, tighten the screw nut and insert the split pin. Then, engage the feed mechanism base and cover on the receiver, insert the fixing bolt, tighten the nut and push the split pin in. 32. To Replace the Trigger Mechanism Frame. Hold the connecting lugs on the frame, put the connecting keys of the frame at the connecting grooves of the receiver and push forward upto the proper position. 33. To Replace the BackPlate Group. Hold the grips with both hands, insert the connecting keys on the back plate into the connecting grooves on the rear of the receiver and set the group in proper position. Insert the fixing bolt of the back plate group. Depress the rear of the receiver with left hand to align the connecting lugs on the trigger mechanism frame with the holes on the gun mount and engage them by the connecting bolt of the gun body. Lay down the rear sight leaf. Pull piston tube to its proper position backward and turn it right to let the retaining lug enter the retaining notch. Tighten the trunnion locking bolts. After the gun is assembled, inspect it. Hold the grip and the trigger with left hand, pull and push the bolt slide by the loading handle with right hand several times in order to check whether the various parts are correctly assembled. **[MECHANICAL FUNCTION OF GUN BODY]** 34. **[In Normal Conditions]** q. The bolt assembly is located at its front position with the locks inserted in the locking recesses and the piston in the gas regulator. r. The return spring is stretched. s. The sear spring extends to force the sear up. t. The long feed arm is limited in the front position by the limiting mechanism and bolt feed slide located at its left. 35. **[During Firing]**. u. **[Loading]**. 19. **[Feeding]**. Insert the linked belt with ammunition into the **[feed mechanism]** through the **[belt holding pawl]** and make the first round held by the belt holding pawl. 20. **[Pulling the Loading Handle]**. When the **[loading handle]** is pulled, it drives the **[bolt slide]** to move backward by catching the **[protuberance]** on the slide. In this case, the mechanical function will be as follows. a. When the bolt slide moves backward, the **[firing pin set]** is brought to the rear along with the firing pin. When **[camming shoulders]** of the firing pin are out of the locks, they will be closed under the action of the **[shaped groove]** and will leave the **[locking recesses]**. The bolt body is carried backward by the slide, thus opening the chamber. At the same time the **[return spring]** is gradually pressed under the action of the piston. b. With the rearward movement of the bolt slide, the **[cocking handle]** on the slide brings the **[long feed arm rearward]**. The long feed arm in turn, forces the **[feed slide to move rightward]** by means of its axle and the short feed arm. At the same time the **[feed pawl]** feeds the first round while the second round is stopped by the **[belt holding pawl]** at the position where the round is to be fed into the feed slot. c. As the bolt slide passes over the sear, the sear spring quickly stretches to force the sear up. Thus, the **sear groove** is **locked** and the bolt assembly is left in the rear. At this moment the gun is ready to be fired. v. **[Firing]**. When the gunner pulls the trigger plate, the **[trigger bar]** raises the **[sear bar up]**, and **[lowers down the sear]** until it is out of the sear groove. At this moment, the bolt slide quickly moves forward under the force of the return spring, producing the following actions. 21. With the forward movement of the bolt slide the cocking handle brings the **[long feed arm forward]**, and through the action of its axle and the short feed arm, moves the **[belt feed slide]** to the **[left]** to catch the next cartridge. 22. When the long feed arm reaches its front position, it is stopped by the **[limiting mechanism]**. 23. As the bolt slide moves forward, the **[firing pin base]** brings the firing pin forward, the **[camming shoulders]** push the bolt locks and the bolt locks in turn forcing the bolt body forward. When the bolt body passes by the **[feed slot]**, the bolt head pushes a cartridge into the chamber, and when the body reaches its position, the extractor catches the rim of the case. At this time, the bolt slide advances further under the force of the spring, bringing along the firing pin. 24. Its **[camming shoulders]** push the bolt locks apart into the **[bolt locking recesses]** and lock the chamber while the **[firing pin strikes]** the **[firing pin head]** and the firing pin head in turn strikes the **[primer]**, thus firing the gun. 36. **[During Automatic Firing]**. After firing, the **[burned propellent]** produces a huge amount of **[powder gas]** which, on one hand, pushes the bullet forward, on the other hand, acts on the bolt assembly through the case base. But the bolt assembly cannot move backward to open the chamber because the bolt locks are still in locking recesses. When the bullet passes over the gas port, a portion of the powder gas, after passing through the **gas port** and the **gas regulator**, pushes the piston and the bolt slide backward. At this instant before the bullet leaves the barrel. the bolt assembly still locks the chamber. As the bolt slide moves backward, the following actions take place. w. The firing pin base brings the firing pin backward. When the **[camming shoulder]** of the firing pin leaves the bolt locks, the bolt locks are closed by the function of the **[shaped groove levels]**. The bolt and bolt slide move further back, thus achieving unlocking. At the same time the return spring is gradually pressed under the action of the piston. x. The bolt body follows the bolt slide backward with the extractor holding the case from the chamber. When the ejector hits against **the bevel surface** of the **receiver**, its end is driven out, ejecting the empty case out of the chamber. y. The **cocking handle brings the long feed arm backward which**, through its **axle** and the **short feed arm**, forces the **belt feed slide** to the right moving the next cartridge to the feeding position, while the following cartridge is stopped by the belt **holding pawl** ready to enter the feed slot. z. The bolt slide hits against the **buffer mechanism** and **compresses** the **buffer spring** to ease the recoil. At this time, because the gunner is still depressing the trigger, and the sear is still in its lowered position, the bolt assembly is driven forward again by the return spring, pushing the cartridge into the chamber, locking the chamber. The firing pin head strikes again at the primer and starts the second firing. **[FAILURE TO FEED]** 37. Then faults occur during firing, pull the bolt assembly to the rear to continue firing. If this attempt is unsuccessful, find out the cause immediately and correct it as quickly as possible. Common faults which occur during firing, and their remedies are listed below. h4  38. **[Precautions Against Stoppages]**. To prevent stoppages during firing and to ensure trouble free operation of the machine gun the following precautions should be borne in mind a. Comply strictly with the instructions on the care of machine gun its storage, cleaning and lubrication. b. During prolonged tiring, if the situation permits, clean the gas ports and regulator periodically. c. During intensive firing, if the barrel is over heated replace it. d. In prolonged firing as well as in the case of repeated stoppages connected with operation of the gas regulator, shift it to the next gas hole. **[AMMUNITION]** 39. **[API]** e. This is used to destroy **aircraft** and **light armoured** targets, and to set them on fire. f. The bullet is made of **steel casing**, **incendiary agent**, **steel core** and **lead jacket**. g. For identification there are **black** and **red** **coloured stripes** on the bullet, indicating Armour Piercing Incendiary cartridge. 40. **[APIT]**. h. The construction and purpose of this round is the same as the one described above except for a **tracer agent** in the bullet and the **incendiary agent in it**. i. The tracer range of the cartridge is **[over 1,000 metres]** with a **[red light]** in flight. **[GEN DUTIES]** 41. **[The Detachment]**. It consists of **[four]** men. j. 1, in **command**. He is responsible for 25. **tactical control**, 26. **selection** and **recognition** of target, and 27. **operation of the computing ruler.\ ** k. 2, **layer for line**, **elevation** and the **firing number**. l. 3, **course model operation** and the **loading number**. m. 4, **ammunition supply number**. 42. **[Responsibilities of Number 1]**. The Number 1 is responsible for the following:- Catchword **[TMFOP]** n. **Tactical handling of the gun** and discipline and efficiency of the detachment o. Proper **maintenance and examination** of the equipment, stores and ammunition p. That the fire from his gun does not **endanger friendly aircraft** and own troops or equipment q. **Supervising the occupation** and **organization** of the gun **position**. r. **Local protection of the gun**, **ammunition** and **detachment**. 43. **[Minimum Detachment Drill]**. s. **[Three Men Detachment]**. The detachment is numbered as 1, 2 and 3. 28. 1 performs the duties of 3 in addition to his own duties. 29. 3 performs the duties of 4. There is no change in the drill. t. **[Two Men Detachment]**. The detachment is numbered as 1 and 2. 30. Number 1 in addition to his own duties, performs the duties of 3 and 4. 31. 2 performs his own duties. u. **[One Man Detachment]**. 32. 1 keeps the **ammunition near the gun** and **fixes the ammunition box with the gun**. 33. He unlocks the traversing and elevation locks. 34. On sighting the aerial target. he sets the course model and fires a short burst. When the danger of the raid is over 35. The ammunition box is replaced by a fresh ammunition box. **[EMPLOYMENT]** 44. The **[air threat pattern]** is based on the **[enemy]**. The weapons they have or can acquire, their capabilities to employ these in terms of time and the ground defenses to be encountered in the combat zone. 45. Read page 63-68 46. 47. **[Principles of Low Altitude Air Defence -- (MAD CFC)]** v. All Round Defence w. Mutual Support x. Defence in Depth. y. Concentration z. Flexibility a. Control and Coordination of Fire 48. **[Mission Considerations for Employment of Resources]**. b. Defence of Mobile Units c. Defence of Fixed or Semi Fixed Vulnerable Points 49. **[Employment Considerations]** -- ( P-DRIER ) d. Determination of Priorities e. Employment of Means f. Defence Design g. Reconnaissance, Selection and Occupation of **Position**. h. Readjustments of **Positions** i. Improvement of **Positions\ ** 50. **[Factors Affecting Air Defence Design by AAMG ]** j. Air Threat k. Terrain. l. Characteristics of Defended Area m. Economy of Resources 51. **[Planning of Air Defence Design]** n. Determine the type of air threat. which includes the type and number of aircraft expected to attack and likely weapons to be used o. Definition of task, that is, to determine the nature, shape and size of the vulnerable point to be defended p. Determine minimum desirable number of weapons required, keeping in mind their characteristics. q. Arrive at a suitable pattern of deployment, without compromising the principles. r. Reconnoiter the area and readjust the positions if required. s. Also select alternative sites t. 36. The number of weapons available with a particular formation/unit may impose a serious limitation whereby additional resources must be asked from the formation. 37. The Planning range for 12.7 mm AAMG is 1600 metres 52. **[Considerations for Siting an AAMG]**. FDL-CCG u. It should preferably have an **all-round clear FIELD OF FIRE**. However, some restrictions may be accepted in directions other than the **primary arc**. v. Maximum **DEPRESSION** at which the machine gun can be laid, must be borne in mind if sited on hills/cliffs where aircraft may be able to approach flying **below** the level of the gun w. The position should have a **LEVEL PLATFORM**. x. **Good CAMOUFLAGE** possibilities y. **Good site for wireless COMMUNICATION** if wireless set is provided. z. It should be suitable for **defence against GROUND ATTACK**. 53. Read page 69, 70, 71 72, 73 54. Armd ops are char by **[fire]** and **[maneuver]**. They advance as rapidly as possible by **[continuous mov]** or **[echeloned mov]**. **[ZEROING]** 55. Fire 8 rds gp with same aim. 56. If 6 x rds hit in any of circles and MPI is near or in white patch, gun is zeroed. 57. There are **[6 indication lines]** marked **left** and **right** of the indicator in front sight of 12.7 AAMG 58. 1mm (distance between on line) horizontal mov on front sight indicates **[9 cm]** on tgt placed at **[100 m]**. 59. You can move **[5 indication lines]** both left and right. 60. This means that horizontal allowable correction is **[45 cm]** both left and right. 61. Vertical allowable correction is **[70 cm both up and down]** 62. **1 mm** (screws) on vertical screw indicates **7 cm** on tgt at **100 m**. 63. There are total **[21 rings / threads]** Read page \# 185 of Methodology Book for Employment in Conventional and Subconventional Warfare