MMG Precis Eng. PDF - Gun Characteristics

RESTRICTED RESTRICTED INDEX 7.62 MM MEDIUM MACHINE GUN MAG-58 Ser Code Subject Page No...

RESTRICTED RESTRICTED INDEX 7.62 MM MEDIUM MACHINE GUN MAG-58 Ser Code Subject Page No No PART- I : GEN 1. Gen - 1 Characteristics of MMG 4 2. Gen - 2 MMG Ammunition and Characteristics of MMG fire 10 3. Gen - 3 MMG Documents 21 4. Gen - 4 MMG siting and Weapon Pit 34 5. Gen - 5 Load Table for MMG Section 40 6. Gen - 6 Danger Area Template For 7.62 mm Ammunition 47 PART- II : MECHANICAL HANDLING 1. M-1 Introduction of the Gun and Tripod 53 2. M-2 Stripping and Assembling thr Gun and its Minor Parts 63 3. M-3 Cleaning and Maintenance 68 4. M-4 Movement of Mechanical Parts (Part-I) 73 5. M-5 Movement of Mechanical Parts (Part-II) 76 6. M-6 Movement of Mechanical Parts (Part-III) 80 7. M-7 Sight Unit 102A/B 85 8. M-8 + Crew Served Weapon Sight 89 9. M-9 Zeroing and Harmonizing 97 PART- III : GUN DRILL 1. GD – 1 Laying Out of Stores, Taking Position, Inspection and Report 105 2. GD - 2 Mount Gun 108 3. GD - 3 Loading, Unloading Action and Cease fire 112 4. GD - 4 Clear Gun and Stand Clear 115 5. GD - 5 Laying and Firing 116 6. GD – 6 Registration of tgt 119 7. GD – 7 Engagement of registered tgt 122 8. GD - 8 Controlled Correction 126 9. GD - 9 Man Pack Carry for Short Distance 128 10. GD - 10 Stoppages Drill And Immediate Action-I 131 11. GD - 11 Stoppages Drill II 135 12. GD – 12 Changing the Barrel 137 13. GD - 13 Relief by Night 138 RESTRICTED  RESTRICTED PART- V : FIRE CONTROL 1. FC - 1 General Principles of Fire Control And Fire Control Orders 141 2. FC- 2 Elevation 144 3. FC - 3 Range Table 148 4. FC - 4 Observation of Fire and Ranging 150 5. FC -5 Stationary targets 155 6. FC -6 Moving Targets 167 7. FC -7 Flanking Fire And Fixed Line 170 8. FC -8 Range Card 178 9. FC -9 Fire Control Chart 182 PART –V : BATTLE HANDLING 1. BH-1 Glossary of Military Terms 192 3. BH-2 Machine Gun in Advance 197 2. BH-3 Recce of Fire Base 199 4. BH-4 Machine Gun in Attack 203 5. BH-5 Machine Gun in in Defence 209 PART-VI : RANGE TABLE 1. RT-1 Appendix ‘A’ 218 2. RT-2 Appendix ‘B’ 219 3. RT-3 Appendix ‘C’ 220 RESTRI1CTED RESTRICTED RESTRICTED GENERAL RESTRICTED  RESTRICTED 4 GEN-1 CHARACTERISTICS OF MEDIUM MACHINE GUN Introduction 1. The key characteristic of machine gun is their high, sustained rate of fire. In 1862 the Gatling Gun was invented which had 6-10 rotating barrel and hence could sustain a hy vol of fire. However, this gun had to be hand cranked. The first truly auto machine gun was the Maxim Machine gun developed by Harim Maxim which worked on the principle of recoil operation and had a water cooled jacket around the barrel. Later, the rights for design of Maxim MG was bought by The Vicker Coy of Britain and after carrying out few modifications on the base design the.303 Viker MG was developed. 2. The.303 Vikers Medium Machine Gun (MMG) was the first MMG to be brought in service in our country which was due to the fact that it was in the British Army since 1912. This weapon fired.303 inch (7.7mm) ball rounds at a rate of 400-500 rounds/minutes and was water cooled. The water cooling consisted of a jacket of water having 4.1 litres of water which boiled after firing the weapon at rapid rate of fire for three minutes continuously. This weapon is obsolete now but occupies a prestigious place in history since all our tactical concepts and doctrines for employment of MMG evolved from the use of.303 Vikers MMG during the First World War. 3. After the successful emp of the Vicker MG many other machine guns were developed across the world like the Browning MG, Chauchat MG, Hotchkiss MG, Lewis MG etc. These machine guns were categorised as hy, med and lt based on the wt of the wpn or the calibre of rd fired. 4. In 1934 the concept of General Purpose Machine Gun originated with German MG 34. By changing the mount (sight and feed mechanism in some cases) the operator could radically transform its function. On a Bipod it was a LMG ideal for inf aslt; on a tripod it could serve as a sustained- fire med machine gun, it could also be mtd on veh and heptr. A Belgium based company Fabrique Nationale introduced the MAG-58 series (Materialized Appui General ‘General Purpose Machine Gun'). This wpn was designed by Ernest Vervier and mfr began by 1958. It could be transformed into LMG or MMG by changing the mount. Due to its successful design more than 80 countries which incl Argentina, Canada, US, UK etc are currently using MAG 58 or its variant. The 7.62 mm MAG-58 was brought into service in India in 1962. They were initially imported but are now being manufacture at Small Arms Factory, Ichapore. This is a very versatile weapon which is also being used by many nations including Belgium, Sweden and US. RESTRICTED  RESTRICTED 5 Aim 5. The aim is to acquaint with the characteristics of MMG. General Description 6. Gun Machine 7.62 mm MAG-58 (a) These are authorised two per Rifle Company or eight in an Infantry Battalion. (b) This is designed to serve role of LMG and Medium MG. However its fired from tripod mtg in MMG mode in India. (c) It fires from open breech thus preventing cook off after prolonged firing. (d) It is fully automatic, air cooled, belt fed, gas operated and capable of sustaining high volume of fire in bursts. (e) Its gas regulation is through gas regulator which makes it possible to vary its rate of fire. (f) The regulator assembly is based on gas exhaust system. Gas is controlled by adjustment of regulator assembly which when set at ‘0’ (fully closed) provides more gas for operating moving parts of the gun. At ‘9’ (fully open) the least amount of gas enters the gas cylinder. At zero setting, maximum 1000 rounds/minutes rate of fire can be achieved. At 6/7, 750 rounds/minutes. Normally it is set on 6/7. (g) Mechanical safety is ensured by a downward tilting locking lever mechanism which provides positive locking (positive locking ensures that the breech is not unlocked even due to vibration). This safety mechanism ensures that primer cap cannot be struck before locking is complete nor the breech end of the barrel be opened before safe pressure is attained within the barrel. (h) The ejection opening cover prevents dust from entering the body when not in use. While firing its automatically opened by the piston extension (i) During firing, flash may be produced from muzzle end or the gas regulator. Flash suppressors are used to reduce flash at muzzle end and the gas regulators are carefully designed to reduce flash. (j) It’s ammunition is linked in disintegrating link belt of 235 rounds and packed in hermetically sealed boxes. (k) Variants presently available in India are (i) Gun Machine (MAG) 7.62mm 2A RESTRICTED  RESTRICTED 6 (ii) Gun Machine (MAG) 7.62mm 2A1 (iii) Gun Machine (MAG) 7.62mm 4A (iv) Gun Machine (MAG TK-71) 7.62mm 5A (only used in tanks) (v) Gun Machine (MAG TK-71) 7.62mm 6A ( Mtd in tanks as well used in grnd role) 7. Mounting tripod 7.62 mm L4 A1 (a) Designed to give stability and more strength. (b) Gun is mounted on it. It is adjusted for low and high mount (13" & 25 ") and air defence role. (c) Incorporated with its own recoil buffer unit. (d) The shoes are designed to grip the grnd thus controlling unwanted movement of the tripod. Mounting Tripod 7.62mm L4 A1 8. Sight Unit -102 A/B. This sight helps to maintain elevation and direction both during night and bad weather conditions. This sight is used by 81 mm Mor. It differs from the erstwhile sight unit C-2 as it is calibrated in degrees. The main differences between sight unit 102 A and sight unit 102 B is that the sight unit 102 A has six spare bulbs whereas sight unit 102 B has 12 spare bulbs. In addition, in sight unit 102 B, leads are covered with an outer Rexene cover. 9. Aiming Post and Lamp. It is used to maintain elevation and deflection when sight unit is used. RESTRICTED  RESTRICTED 7 Capabilities 10. Light Weight. As per its capability this weapon is the lightest in its family. It can be easily carried by a detachment of three persons for some distance. Weight of different accessories/components is as under:- (a) Total weight of gun - 24.7 Kg (b) Gun 2A1 - 10.5 Kg (c) Tripod - 14.2 Kg (d) Barrel 2A1 - 3.3 Kg (e) Belt - 6.8 Kg (f) Belt with box - 9 Kg (g) SU 102 A - 6.6 Kg (2.5 kg/unit) (h) SU 102 B - 6.75 Kg (j) Aiming post - 1.35 Kg (k) Aiming lamp - 4.5 Kg 11. Long Range. Maximum range -3900Mtr & effective range 1800Mtr. Achieved by (a) Lethality of Amn. The residual descent velocity at 3900m is 107m/s. This implies that the bullet is lethal throughout the trajectory in this max rg. (b) Precision & Accuracy. The tripod mount and hy parts provides it stability resulting in precise fire at long ranges. The open sight allows accurate aiming upto a dist of 1800m. 12. Heavy Volume of Fire. It is capable of sustained and heavy volume of fire in bursts due to:- (a) Being belt fed, belt links can be easily joined or broken to give belt any desired length. (b) Robust parts and fewer stoppages. (c) Spare barrel. Changed after firing of four belts continuously. (d) Heavy barrel can withstand higher temp and is cooled by prevailing air. 13. Rate of Fire. It means number of rounds fired in a given time. It depends on setting of gas regulator and pause between firing. Three types of rate of fire are:- (a) Cyclic. On pressing of trigger, rounds are fired at a rate of 600 to 1000 rounds/minutes depending on the setting of gas regulator. (b) Normal. 100 rounds/minutes; trigger pressed for two to three seconds and pause for 10 to 12 seconds OR trigger pressed for one second and pause for 5 to 6 seconds. RESTRICTED  RESTRICTED 8 (c) Rapid. 200 rounds/minutes; trigger pressed for two to three seconds with a pause for 5 to 6 seconds OR trigger pressed for one second and pause for 2 to 3 seconds. 14. Flexibility. This weapon has the ability to switch from one type of target to another in very short time. Weapon has day and night firing capability and can switch from ground role to air role in very short time. The tripod helps in achieving under mentioned functions:- (a) Free traverse - 360 degree (b) Free elevation - 22 degree (c) Free depression - 11 degree (d) Controlled traverse - 11 degree (e) Controlled elevation/depression - 5 degree Limitations. 15. Flash. It is caused by inflammable gases produced by burning of propellant. These gases when combine with atmospheric oxygen burn with a flash which can be seen from far distance. (a) Flash Suppressor attached to muzzle minimizes flash. (b) Design of gas regulator assembly minimises some flash caused by the exhaust gas. 16. Smoke. It occurs due to burning of hydro carbons i.e. oil in the barrel or old ammunition. 17. Sound/muzzle Blast. When high pressure gas leaves the muzzle and comes in contact with the low pressure gas outside with a force, noise is produced. Flash/smoke/muzzle blast discloses gun position therefore correct siting, camouflage and concealment assume importance. Sprinkling of water at front of gun position avoids dust from rising. 18. Breakage of Parts. Though major parts of the weapon are robust, small parts like firing pin, ejector, extractor can break due to high rate of fire or mishandling. So high rate of fire should only be resorted to when required. Regular maintenance of weapon and careful handling avoids breakages. A spare part wallet is also provided with the gun for accessories. 19. Overheating of Barrel. Due to high rate of fire the barrel may over heat. Barrel should be changed after firing four belts continuously at any rate. RESTRICTED  RESTRICTED 9 Note: To overcome few of the limitations of the wpn, they can be emp in pairs (sec gun) such that they alternately bring down fire on the tgt, with one gun firing during the pause of the other. This would ensure that neither gun is over stressed nor continuous fire is brought down on the tgt. Conclusion 20. To optimally utilize any weapon system, it is of paramount importance that one is well aware of the characteristics and limitations of that weapon. Knowing the characteristics and limitations, the weapon can be effectively employed in various battle scenarios. RESTRICTED  RESTRICTED 10 GEN-2 MMG AMMUNITION AND CHARACTERISTICS OF MMG FIRE Introduction 1. Having learnt the characteristics of the MMG, it is imperative for us to know about the ammunition fired by the weapon and the characteristics of its fire. This will help the gun numbers and the detachment commanders to use the weapon to its optimum capability and engage targets effectively without wasting time and ammunition. Aim 2. To acquaint the class with the ammunition fired from the MMG and the characteristics of its fire. Parts 3. The lesson will be covered in two parts:- (a) Part-I - Ammunition. (b) Part-II - Characteristics of MMG Fire. Part - I : Ammunition 4. Types of Ammunition. The six types of ammunition fired from the gun are Ball, Tracer, Blank, AP, SLAP and Incendiary. Of these only the first three are used in India. A brief on all types is given below:- (a) Ball. This ammunition is anti-personal and can also be used against soft skinned vehicles. The ammunition is named so as in early times the ammunition, which used to be muzzle loaded, was of the shape of a ball. (b) Tracer. This ammunition is used to indicate targets and observe fire with the help of a red flare that follows the bullet. The flare can also be used for incendiary purposes, though only till 1150 m. (c) Blank. But for the bullet, which is absent, this ammunition is like ball ammunition. This is used to simulate automatic fire in exercises, demonstrations and battle inoculation. Blank Fire attachment is placed on the muzzle end for auto fire. RESTRICTED  RESTRICTED 11 (d) AP. This is an armour piercing ammunition which can be used against Infantry Combat Vehicles (ICVs) and soft skinned vehicles. Kinetic energy is used by the bullet to pierce the armour plating. To facilitate piercing, the bullet is made of harder alloy. (e) SLAP. SLAP stands for Sabot Light Armour Piercing. This ammunition is encased in a sabot which is discarded during the flight of the bullet. This ammunition also uses the kinetic energy to penetrate. Due to the reduced cross section of the projectile it has better penetration. (f) Incendiary. This ammunition is used to initiate fire at the target end. It has a blue tip for identification. Ball Ammunition 5. Data (a) Length - 71 mm (b) Weight - 23.13 + 0.65 gm (c) Diameter - 11 mm or 1.1 cm 6. Parts (a).22 Cap/Primer cap. (b) Cartridge case. (c) Bullet. Bullet Crimp Brass Case Propellant Primer Rim Cross Section of Ball Ammunition RESTRICTED  RESTRICTED 12 7. Primer Cap (a) Need. The propellant charge in cart case is a low explosive and is initiated by heat. However, for reliable and efficient design, weapons are generally made to initiate the ammunition by impact. Hence, primer caps are used to convert the impact into the heat required to initiate the propellant charge. (b) Description. (i) It is made of copper and is press fitted in the base of the cartridge case. (ii) The diameter of the cap is.22 inches. (iii) It is a centre fired boxer type percussion cap i.e. impact and friction are required to initiate it. (iv) The cap contains the fwg:- (aa) Explosive. A mixture of chemicals with a trade name FA-956 (Frankford Arsenal) and is non fulminate type. This is less volatile and more stable than Mercury Fulminate and has a shelf life of 15-20 years. A minimum pressure of eight lbs/sq inch is required to initiate this charge. This ensures safe handling, transportation and storage. (ab) Flash Hole. The hot slag/ flash produced in the cap on initiation is passed to the propellant charge in the cart case via the flash hole. (ac) Tin Foil Disc. It prevents the exp mixture from seeping out of the flash hole when not initiated. Upon initiation of the cap is melts down. (ad) Anvil. It acts as a rigid base upon which the exp mixture is struck by the firing pin. MAIN CHARGE FLASH HOLE TIN FOILNDISC FA 956 Cut Section of a Primer Cap RESTRICTED  RESTRICTED 13 (c) Working. On impact of the firing pin on the primer cap with required force, the outer casing dents inwards and pinches the primer mixture between the anvil and itself. The high explosive in the primer mixture initiates on impact and produces hot gas and slag which passes onto the propellant charge in the cart case through the flash hole. In their simplest form, FA 956 has the fwg components :  Primary explosive -- lead styphnate.  Sensitizer – tetrazene  Fuel – antimony trisulfide, aluminum powder, etc.  Oxidizer –barium nitrate  Binder – Gum Solution The role of the primary explosive, almost always lead styphnate in either the normal or basic form, is to provide an extremely rapid release of energy in the form of heat and pressure. Because lead styphnate is not sensitive enough on its own to initiate reliably in a typical primer configuration, a sensitizer is included; typically, this is the weaker but more sensitive explosive tetrazene (1-(5tetrazolyl)-3-guanyl tetrazene hydrate). The fuel/oxidizer combination is necessary in order to increase the heat and slag output required to smoothly ignite the propellant. The most common fuel is antimony trisulfide, chosen not only for its useful combustion properties but also for its sharpedged crystal morphology which provides added friction sensitivity to the mixture. The oxidizer is almost always barium nitrate, which was selected in the early twentieth century as a replacement for the previously used potassium chlorate (KClO3) because it is not only non-hygroscopic but also does not form halogen salts as byproducts (many halogen salts absorb water from the atmosphere, and their residues were blamed for gun barrel corrosion). Finally, because of the varying densities and other properties of the disparate formulation ingredients, a suitable polymeric binder is required to maintain both the homogeneity and integrity of the primer formulation. This is generally Gum Arabic or a similar natural extract. Outside of the core formulation, other additives are often included. For instance, aluminum powder is frequently added as a more reactive fuel to boost energy output 8. Cartridge case (a) General. The cartridge case is made of brass (copper 70% and zinc 30%) and is 51 mm in length. It is tapered from the front for easy extraction and high rate of fire. The functions of the cartridge case before and after firing are mentioned in the succeeding paragraphs. (b) Function of cartridge case on loading (i) Holds the bullet and the main charge. (ii) Protects charge from atmospheric reaction. (iii) Provides means of extraction. (iv) Acts as an insulator between the wall of the chamber and charge to prevent “Cook Off” (heated up barrel may initiate the ammunition accidentally which is known as “Cook Off”). (v) Locates/aligns the bullet in the chamber. RESTRICTED  RESTRICTED 14 (c) Functions of cartridge case during/after firing (i) Prevents erosion of chamber, breech face and firing pin. (ii) Absorbs approximately 30% of heat produced. (iii) Helps in obturation (Prevents rearward escape of gases). (iv) Acts as a mean for extraction. (d) Reason for the cart case being made of Brass (i) It is cheap and available easily. (ii) It oxidizes immediately on manufacture forming a protective coating of zinc oxide which prevents further corrosion/rusting. (iii) It is reusable. (iv) Its linear co-efficient of expansion is high thus it expands fast and helps in obturation. (v) It absorbs heat. (vi) After firing it contracts fast, thus helping in extraction. (e) Markings On Base of Cart Case (i) Lot No. (ii) Calibre. (iii) Factory code. (iv) Yr of manufacture. 9. Nitro Cellulose Ch. The main/ propellant charge is granular and non hygroscopic in nature. The charge weighs 2.85 gm and is single base. 10. Bullet. The bullet is made of two parts viz. core and jacket. It weights 9.33 +/- 0.13 gm, its length is 29 mm and the diameter is 7.84 mm. The diameter is slightly more than the bore of the weapon to facilitate in set up. (a) Core. The core is the inner portion of the bullet. It is made of 90% lead and 10% antimony. Lead is used because of its high density resulting in more mass of the projectile for a given calibre. Antimony is added for the following reasons:- (i) To make the bullet hard. RESTRICTED  RESTRICTED 15 (ii) For ease in casting during manufacture. (b) Jacket. The core of the bullet is covered by a jacket made of gilding metal (90% copper and 10% nickel). The reasons for having a jacket over the core are as follows:- (i) Lead, though dense, is a soft metal which could easily deform or get deposited in the bore of the barrel. (ii) Gilding metal is relatively soft and thus doesn’t erode the barrel (in case the core is made out of harder metal/ alloys). (iii) Assists in set up i.e. since the size of the bullet is slightly larger than the calibre of the barrel, the jacket of the bullet, upon being pushed into the barrel by the high pressure gas, deforms and fits into the lands and grooves of the barrel preventing forward escape of gases. (iv) Due to setup spin is imparted on the bullet on its forward motion. (v) It helps in maintenance of shape of the bullet. (vi) To meet the criteria of The Hague Convention which prohibits use of bullets which expand/flatten in body. 11. Firing of a Round. When the firing pin strikes the primer cap, a flash is produced which is passed through the flash hole and it ignites the propellant charge. The propellant charge then burns rapidly thereby producing gases and thus increasing the pressure in the cartridge case. The cartridge case expands and hug the walls of the chamber preventing rearward escape of gas and once the rd is pushed into the barrel setup occurs. Due to high pressure, the bullet is propelled forward. The spin imparted to the bullet provides stability during flight. Tracer Ammunition 12. The tracer ammunition looks similar to the ball amn, to differentiate, its tip and base are painted red. The length of the bullet is 35 mm of which 15mm is in the cartridge case. The weight of the bullet is 23.13 +/- 0.65 gms. There is no change in the primer cap and the cartridge case of the tracer ammunition and the ball ammunition. However, a brass delay disc, sub igniter and the tracer element is added in the bullet of the tracer ammunition. RESTRICTED  RESTRICTED 16 Primer Cartridge Case Bullet Propellant Charge Brass Delay Disc Sub Ignitor Tracer Element 7.62mm Tracer Ammunition 13. Brass Delay Disc. A brass delay disc has been placed at the base of the bullet of the tracer ammunition. The functions of the disc are as under:- (a) To hold the sub igniter in the core of the bullet. (b) To separate the sub igniter from the main charge. (c) To prevent burning of the sub igniter in the barrel. (d) Absorbs the heat passed by the main charge and after reaching the threshold of ignition it initiates the sub igniter. 14. Sub Igniter. It weighs three grains and is a dark ignition type of chemical i.e. Barium Nitrate which does not give light or smoke on ignition. It burns from the muzzle upto 50 m and then passes the flash to the tracer element. The purpose of incorporating the sub igniter is as under:- (a) Prevents the firer’s eye from dazzling effect and injury. (b) Prevents in giving out the position of the weapon. 15. Tracer element. It weighs 14 grains. It burns for 2.6 seconds and gives a red glow from 50 m to 1150 m. It is used for indication of targets, observation of fire and for incendiary purposes. The Tracer element is a mixture of Magnesium powder, Strontium Nitrate and polyvinyl chloride. Magnesium Powder acts as a base, Strontium Nitrate acts as oxidizer and produces red light. The reaction of this mixture is too energetic, consuming all material in one big flash of white light (white light is due to the burning of Magnesium powder). Therefore to ensure that red colour light of Strontium Nitrate is not overpowered by Magnesium powder, a chlorine donor such as polyvinyl chloride is used to cool down the reaction. RESTRICTED  RESTRICTED 17 16. Working. On firing of a tracer round the heat is passed on to the Brass Delay Disc from the propellant. The disc then passes the heat to the sub igniter during the time bullet travels through the barrel. The sub igniter burns from the muzzle upto 50 m. This is also known as the Dark Ignition Phase. After 50 m the flash is passed to the tracer element which then glows till 1150 m. The bullet is not made to glow after 1150 m because the external ballistics of the round becomes too unpredictable at long ranges due to the continuous change in the centre of gravity. Blank Ammunition 17. The blank ammunition is used to simulate the fire effect of MMGs during training, exercises and battle inoculation. Auto fire simulation can be achieved by removing the flash suppressor and screwing the blank firing attachment on the barrel which prevents escape of gases from the muzzle end. There is no bullet in this ammunition and the cartridge case is crimped in the front. Primer Cartridge Case Crimped Portion Propellant Charge Blank Ammunition Part-II : Characteristics of Fire 18. Trajectory. The two main forces acting on the bullet during flight are air resistance and gravitational pull. The gravitational force causes the parabolic path while the air resistance makes it into a deformed parabola with a steeper descending curve. This path followed by the bullet in flight is called the trajectory. 19. Culminating Point. The highest point in the trajectory is called the culminating point. It is measured from the line of sight. It occurs at a point approximately 2/3 of the range for longer range (i.e. above 1000 m) and at approximately 1/2 of the range at lower range. The culminating point is at 1.2meter (4 ft) at 600 m and 25 ft at1800 m. Thus, to achieve grazing fire the range applied on the gun when it is on fixed line is 600 m. 20. Cone of Fire. Owing to the vibration in the gun and different quantum of external forces acting on bullets, no two bullets follow the same trajectory. The outer profile of all the trajectories followed in a single burst forms a shape of a curved cone with vertex at muzzle RESTRICTED  RESTRICTED 18 end and the Beaten Zone as the base. This is known as cone of fire. Most of the bullets are in the centre of the cone. 21. Beaten Zone. When a number of rounds are fired by gun at one range then the pattern formed by the bullets on striking the ground is called Beaten Zone. It is oval in shape. The Area within which 85-90% rounds fall is known as the Effective Beaten Zone. Effective beaten zone has an angular width of 2mils. Thus, the width of the beaten zone increases with the increase in range. Due to the flatness of trajectory, at shorter ranges the beaten zone is elongated. However, as the range increases, the trajectory becomes more curved and the angle of descent increases thus decreasing the length of the beaten zone. The dimension of Effective Beaten Zone is as under:- (a) 600 m - 100 m x 1 m (b) 1000 m - 75 m x 2 m (c) 1500m - 55m x 3m (d) 1800 m - 50 m x 4 m 22. First Catch. The point on the ascending or descending branch of the trajectory which has the same ht from the grnd as that of tgt. 23. First Graze. It is the point on the ground where the bullet first strikes the ground. It depends on the configuration of the ground behind the target. It is always in the descending branch of the trajectory. 24. Dangerous Space. The area between the first catch and the first graze is called the dangerous space. 25. Dangerous Zone. The total area covered by the dangerous space and beaten zone is called the dangerous zone. Various factors affecting the dangerous space and dangerous zone are as under:- (a) Height of the target. When the height of the target is more than the gun, the dangerous space is more. (b) Height of the gun. When the gun is at a higher height than the target, the dangerous space reduces. (c) Range. The dangerous space decrease as the angle is increased and vice versa. (d) Flat trajectory. Flatter the trajectory more will be the dangerous space. RESTRICTED  RESTRICTED 19 (e) Ground configuration. The dangerous space is more if the ground behind the target is sloping downwards and less if it is sloping upwards. Trajectory 26. Grazing Fire. The kind of fire effect in which danger zone exist over the entire length of trajectory, barring few dead grounds. The max dist upto which grazing fire is possible on level ground is 600-700m, at ranges more than this the culminating pt rises more than 4-4.5 ft. Grazing Fire 27. Plunging Fire. The kind of fire effect in which Danger Space is almost negligible and the Danger zone is limited to the Beaten Zone due to very steep angle between descending trajectory and ground. This is generally seen while firing from a high ground to low ground or abruptly rising ground. RESTRICTED  RESTRICTED 20 Plunging Fire 28. Enfilade Fire. Fire of a weapon from a flank, sited to sweep a target along its longer axis. Conclusion 29. If the firer knows about the characteristics of the ammunition and its fire he can use the same in engaging the targets effectively in all conditions without wastage of time and ammunition. RESTRICTED  RESTRICTED 21 GEN- 3 MMG DOCUMENTS Introduction 1. For maintenance of every weapon and to avoid problems during handing/taking over it is necessary to carry out timely repair, battle readiness and demand of damaged parts. It is also necessary to carryout timely documentation. The record of repairs, maintenance, inspection, issue, handing/taking over and the condition of weapon is maintained. Aim 2. To acquaint with the documents maintained for 7.62 mm MMG MAG 58. Parts 3. The lesson will be covered in two parts:- (a) Part-I- Advantages of documentation. (b) Part-II- Documents for MMG. Part-I : Advantages of Documentation 4. The advantages of proper documentation are as under:- (a) Timely repairs and inspection of the weapon can be carried out. (b) The responsibility of maintenance of gun is known. (c) Commander comes to know about the condition of weapons. (d) Life of the weapon increases and weapon remains in serviceable condition. (e) Demand for the broken/unserviceable parts can be placed in time. RESTRICTED  RESTRICTED 22 Part-II : Documents for MMG 5. Complete Equipment Schedule (CES) IAFF-980. This document is kept in Quarter Master’s office in unit. It contains details of that particular weapon, its parts, spare parts, tools and other relevant details (Literature). (a) Annotations. They are given as under:- (i) E - Expendable stores, consumable items, non-ledger small spare parts. (ii) X - These are those important spare parts without which ordnance does not issue the weapon. (ii) R - These items are issued by Engineers. (b) Parts. CES is divided into four parts:- (i) Part-II : It is the index of the remaining three parts. (ii) Part-II : It has a list of major parts authorised with the weapon. (iii) Part-III : It contains the following parts:- (aa) List of spare parts. (ab) Tools. (ac) Literature. (iv) Part-IV : This part gives details of Part-II e.g. two bulbs are auth with one sight so where they shall be used. 6. Index Card (IAFZ-3015). It contains gun’s registration number, unit serial number, type of weapon, issue and receipt voucher’s date and voucher number (Refer Appendix ‘A’). To prepare Index card following should be ensured:- (a) One Index card should be prepared for each gun. (b) With the issue of new gun new index card to be prepared and kept in Quarter Master office. (c) When gun is handed over/transferred to the other unit, it should be done on a new index card and receipt/issue voucher number and date to be filled in the old index card. 7. Electrical & Mechanical Engineering Regulations (INDIA) (EMERs). This is issued to every unit and is generally kept in Quarter Master office or armourer shop. RESTRICTED  RESTRICTED 23 Whenever the amendments come it should be amended. It contains the under mentioned details:- (a) Technical data of the gun. (b) Procedure of inspection and repair of gun. (c) Instructions to for zeroing. (d) Technical data of the various parts of the gun. 8. Weapon History Sheet (IAFO-1410). Detl of breakages, Section Commander’s initial and armourer’s remarks (Refer Appendix 'B'). 9. Firing Record Register. Number of rounds fired and on which date. 10. Inspection documents. Inspection documents are of three types:- (a) IAF (EME) E-05. These documents are prepared by unit for unit armourer/field repair workshop in duplicate and for AIA inspection in triplicate (Refer Appendix 'C'). This document contains the under mentioned details:- (i) In Part-I and Part-II from column 1 to 5 all unit weapons and their registration numbers are filled, rest all columns are filled by the inspecting officer. (ii) After inspection, one copy of the inspection report is kept by the inspecting officer, one copy is handed over to the unit Quarter Master and third copy is forwarded to the field repair workshop for R-2 repairs if EMAE (SA) inspection is carried out. (b) IAF (EME) E-20. These document are prepared for annual technical inspection which is carried out by EMEA (Small Arms) on behalf of formation commander (Refer Appendix 'D'). It contains the following details:- (i) Types and quantity of weapons inspected. (ii) Previous year’s inspection report. (iii) Condition of armourer shop. (iv) Maintenance state of unit weapons. (v) Present year inspection report. (vi) Formation commander’s remarks. (c) IAF (EME) E-25 (Condemnation Report) (i) These document are prepared by the unit for field repair workshop in quadruplicate (four copy), when weapon is declared BLR/BER. RESTRICTED  RESTRICTED 24 (ii) After being declared BLR/BER, four copies are prepared wherein one copy for demand, one copy for weapon back load, one copy for unit and one copy is send for workshop records. Its format is given in Appendix ‘E’. Conclusion 11. Documentation of weapon is carried out for regular maintenance of weapon to keep it in a serviceable condition at all times. Advantages of documentation can only be achieved if all entries are made regularly and not just before inspection. The commander gets complete knowledge of weapon state from documents. In company the maintenance of documents is the responsibility of Company Commander and respective Section Commanders. RESTRICTED RESTRICTED 25 RESTRICTED  RESTRICTED 26 Appx ‘B’ (Ref Para 8) WEAPON HISTORY SHEET IAFO- 1410 RESTRICTED RESTRICTED 27 RESTRICTED  RESTRICTED 28 Appx ‘C’ Ref Para 8(a) IAF (EME) E-05 RESTRICTED RESTRICTED 29 RESTRICTED RESTRICTED 30 Appx ‘D’ (Ref para 9(d)) IAF (EME) E-20 RESTRICTED RESTRICTED 31 RESTRICTED RESTRICTED 32 Appx ‘E’ (Ref Para 9(c)) RESTRICTED  RESTRICTED 33 Notes (a) The certificate will be prepared in quadruplicate and distributed as under:- (i) Original - To accompany the demand and distributed as under. (ii) Duplicate - To accompany the items sentenced BER/UNSV when returning stores to ordnance salvage. (iii) Triplicate - To be retained by the unit. (iv) Quadruplicate- To be retained by workshop for record. (b) The certificate will be signed by OC Workshop or an officer on his behalf. (c) Separate certificate will be prepared for stores pertaining to different VAOS sections and for fair/unfair wear and tear. (d) In case of stores sentenced BLR/BER due to unfair wear and tear, action will be taken in accordance with ER(I) Part I, Para 52(i). RESTRICTED  RESTRICTED 34 GEN-4 MMG SITING AND WEAPON PIT Introduction 1. To make the best use of weapon in any operation of war it is important that both the firer and the weapon are kept safe and the weapon is capable of providing maximum fire within its arc of fire. To make the best use of MMG it is important that the MMG weapon pit is sited properly. The design should be such that it is able to provide effective fire on to the enemy. If time permits then shelter for the troops and overhead protection (OHP) should also be prepared. Aim 2. To acquaint with the MMG weapon pit for ground role as well as anti-aircraft role. Parts 3. The lesson will be covered in two parts:- (a) Part-I - MMG weapon pit for ground role. (b) Part-II - MMG weapon pit for anti-aircraft role and method of engaging air targets. Part-I : MMG Weapon Pit for Ground Role Siting Principles 4. Following points should be taken into consideration to site MMG:- (a) It should be able to perform the assigned task. (b) Belt of fire should be close to the defences and should be able to achieve grazing fire. (c) If there is dead ground in front then it should be covered with other weapons available. (d) If possible it should provide enfilade fire. RESTRICTED  RESTRICTED 35 (e) Position should be defiladed from enemy’s direct firing weapons. (f) The neighbouring gun should be in mutual support. (g) It should be under protection from air and ground attack. (h) Field of fire should be clear. (j) It should be away from any prominent land mark. (k) It should not be on sky line. (l) It should have local protection. (m) If required then alternate position and secondary position should be prepared. (n) Route in and route out should be under cover. 5. Dimensions for MMG weapon pit for Ground role is given in Sketch 'P'. MMG Pill Box 6. In field areas infantry battalions may have to prepare permanent defences. In defence, pill boxes along with the weapon pit provide living for the troops. Whenever pill boxes are prepared it should be ensured that MMG is able to provide effective fire completely in an arc of 270 degrees. Part-II : MMG Weapon Pit for Anti Aircraft Role and Method of Engaging Air Targets Siting Principles 7. Though MMG cannot provide anti aircraft protection but it can prove to be dangerous for low flying aircrafts, Remotely Piloted Vehicles (RPVs) and helicopters. In defence this role is given to those guns which are deployed in depth or are deployed on the least likely approach of the enemy. To select a location for MMG in anti-aircraft role following needs to be considered:- (a) Position should have adequate cover from ground and air observation. (b) Position should be comfortable. (c) It should provide effective fire on to the expected routes of the enemy aircraft. (d) Alarm signal should be tied up. (e) Position to be in depth and should be able to provide fire support to other guns. RESTRICTED  RESTRICTED 36 (f) If need arises weapon should be able to fire in ground role. 8. Approach routes of aircraft To destroy enemy aircraft it is important for us to know the characteristics of enemy aircrafts and also their attacking techniques and their approach routes which are as under:- (a) Along the valleys. (b) Between the gaps in mountains. (c) From the direction of Sun. (d) Gaps inside jungles. (f) From rivers and nalas. 9. Height. When aircraft is 400 to 1500 m away then its height from the ground is generally 1000 ft and by the time it reaches the target its height becomes 150 to 300 m and this is the ideal time to fire on to the target. 10. Speed. The speed of aircraft is categorized into three:- (a) High Speed. The aircraft which has a speed of more than 830 km/hr like fighter bomber. (b) Medium Speed. The aircraft which has a speed in between 365 km/hr to 830 km/hr e.g. Dakota or other commercial aircrafts. (c) Slow Speed. The aircrafts which has a speed of 365 km/hr or less like helicopter MI-18. 11. Target. It appears to be like a point at far distance. How it shall appear at close distance depends on terrain, weather and its direction. Tgt shall appear for only 2 to 3 sec. 12. Method of Fire. One single medium machine gun is not capable of destroying a target. Therefore all medium machine guns and light machine guns which are deployed in anti aircraft role should fire on the route in and route out of the target so that chances of destruction are more. 13. Lead. To fire effectively on to the enemy aircraft it is important that correct lead is applied on to the gun. Quick application of lead depends upon experience, skill and training of the firer. Lead should be applied as mentioned below for aircrafts moving at varying speeds:- (a) 30 times of the aircraft flying in high speed. RESTRICTED  RESTRICTED 37 (b) 12 times of the aircraft flying in medium speed. (c) 8 times of the aircraft flying in slow speed. 14. Range. MMG to be layed in the direction of the approaching aircraft and if the range is 1000 m then range applied on the rear sight should be 200 m. 15. Points to be considered for laying the gun in anti-aircraft role:- (a) Long leg to be in front. (b) Tripod to be in high mount. (c) Gas regulator setting to be on '0'. (d) Cradle locking lever should be open. (e) Bracket screw to be left open. (f) Front mounting pin should be towards the firer. 16. The sketch of MMG weapon pit for anti aircraft role is given in Sketch 'Q'. Conclusion 17. MMG weapon pit should be sited keeping in view the siting considerations so that during war maximum benefit can be taken out of the weapon. RESTRICTED  RESTRICTED 38 WEAPON PIT FOR GRND ROLE RESTRICTED  RESTRICTED 39 WEAPON PIT FOR ANTI AIRCRAFT ROLE 2’ 4’ 2 ’ 8’ 4’ 4 1/2’ 4 1/2’ 2’ 2’ Cut Section of Weapon Pit for Anti Aircraft Role RESTRICTED  RESTRICTED 40 GEN-5 LOAD TABLE FOR MMG SECTION Introduction 1. As we know that the terrain close on our International Border is not similar throughout, therefore in war it shall be required to carry MMG, ammunition and other items of the section by various methods as per the terrain configuration. Though we cannot dictate the method to carry load but the lesson shall give the details of carrying load in an organized manner. The commander detailed should have the complete details of the items loaded along with the Nos so that if required the items can be taken out without delay. It should also be ensured that the loaded items do not get damaged during transport. Aim 2. To acquaint with the details of load table of MMG section. Parts 3. This lesson will be covered into four parts:- (a) Part-I - Carrying of load by manpack. (b) Part-II - Carrying of load in vehicle. (c) Part-III - Carrying of load by animal transport. (d) Part-IV - Carrying of load by BAUT. Part-I : Carrying of Load by Manpack Carrying of MMG in Man Pack State 4. Usually in mountainous terrain and in special mission MMG needs to be carried in a man pack state. Extra ammunition either has to be distributed within the rifle company or ponies/porters have to be arranged. 5. The section carries its load in the under mentioned manner RESTRICTED  RESTRICTED 41 Load of a Section (a) Section Commander. Personal weapon (9 mm CMG), bayonet and pouch ammunition, binocular, compass, pointer staff, map, map case and writing material and two belt boxes. (b) Detachment Commander. Personal weapon (9 mm CMG), bayonet, pouch ammunition, aiming post with aiming lamp and two belt boxes. (c) Gun No 1. Personal weapon (9 mm pistol) with pouch ammunition, tripod and one belt box. (d) Gun No 2. Personal weapon (9 mm CMG), bayonet, pouch amn, sight unit with case and gun along with spare barrel and spare parts wallet. Part-II : Carrying of Load in Veh Load Table for a Jeep 6. In mountainous terrain at times it may not be possible to carry load in large vehicles therefore small vehicles like jeep may be allotted. Detachment load can be loaded in one Jeep. Load table for the same is given below:- S No Items Qty Weight (kg) 1. MMG with tripod and spare barrel 01 28.000 2. Sight unit 102 A/B 01 6.600 3. Aiming Post 01 1.350 RESTRICTED  RESTRICTED 42 S No Items Qty Weight (kg) 4. Aiming Lamp 01 4.500 5. Detachment Nos 03 300.000 6. Spare Parts Wallet 01 1.000 7. Belt Box 18 234.000 8. Net Camouflage 01 6.300 9. Pickaxe 01 3.600 10. Shovel 01 1.800 11. Sand Bags 25 5.200 Total - 592.350 Note :- Three men other than Driver. Load table for 2.5 Ton 6. The complete section with battle load can fit in one 2.5 ton vehicle.Load table for the same is as below. S No Items Qty Weight (kg) 1. MMG with tripod and spare barrel 02 56.000 2. Sight unit 102 A/B 02 13.200 3. Aiming Lamp 02 9.000 4. Aiming Post 02 2.700 5. Section troops 07 700.000 6. Spare Parts Wallet 02 2.000 7. Belt Box 36 324.000 8. Net Camouflage 02 12.600 9. Pickaxe 02 7.200 10. Shovel 02 3.600 11. Sand Bags 50 10.400 Total - 1140.700 * Load of AGS section can also be adjusted in 2.5 Ton. 7. While loading a 2.5 Ton following points should be considered:- (a) Light items should be kept over the heavy items. (b) The items required initially should be kept close and on top. RESTRICTED  RESTRICTED 43 Part-III : Carrying of Load on Mules 8. In mountainous terrain where the vehicle cannot go and there is a need to carry heavy load then the only option left to carry the load comfortably is through Mules. 9. Types of Mules are of two types:- (a) Mule MA (Arty). It is capable of carrying 145 kg in plains and 108 kg in mountains. (b) Mule GS. It is capable of carrying 72.5 kg in plains and 54 kg in mountains. To carry a section load 12 Mule GS are required. For a detachment, six GS Mules are required. Its distribution is as under:- (i) Gun Mule - 01 (ii) Ammunition Mule - 04 (iii) Miscellaneous - 01 (2 x belt boxes, digging tools and other administration related items). 10. The load of a mule is divided in three parts as (a) Left Load. (b) Right Load. (c) Top Load. Load carried by Mule RESTRICTED  RESTRICTED 44 11. Details of loads carried by each mule are given below. Gun Mule Ammunition Mule Miscellaneous Mule Wt S Wt S Wt S No Items Qty Items Qty Items Qty (kg) No (kg) No (kg) Left Load Left Load Left Load Gun & Belt (a) Spare 01 13.800 (a) 02 18.000 Box Barrel Net (b) Camouflag 01 6.300 Belt e (a) 03 27 Box (b) Shovel 01 1.800 Aiming (c) 01 01.350 Post Aiming Sand (d) 01 4.500 (c) 15 3.120 Lamp Bags Total 25.950 Total 27 Total 22.920 Right Load Right Load Right Load Belt (e) Tripod 01 14.200 (d) 02 18.000 Box Pick (f) Sight 01 6.750 Belt (e) 01 3.600 (b) 03 27 Axe Box Sand (g) Sand Bags 15 3.12 (f) 05 1.040 Bags Total 24.92 Total 27 Total 22.64 Top Load Top Load Top Load Sand (h) Sand bags 10 2.080 - (g) 05 1.040 bags Total Net wt 51.950 Total Net wt 54.000 Total Net Wt 46.960 12. Loading of a Mule. When ordered 'Prepare to Load' the Numbers come to their respective location and Number 1 and Number 2 together load the mule. Detachment commander after loading the top load ties the complete load. 13. Points to be kept in mind while loading. (a) Load should be tied up properly. RESTRICTED  RESTRICTED 45 (b) Load to be equally distributed on both sides. (c) No noise should come while the mules are on move. (d) No item should prick the mule. (e) No individual should be behind the Mule while loading. (f) The load should not be kept on mule for more than four hours. 14. Unload. When ordered 'Prepare to Unload' the Nos come to their respective location. First the top load is removed and then the remaining load is removed. Part-IV : Carrying of Load by Baut 15. Many times the situation arises when during river crossing the load needs to be carried on a BAUT. To ensure that no accident takes place it is important that the loading and unloading drills are known. Boat assault universal type (BAUT) 16. Things to be kept in mind while loading. (a) BAUT to be properly anchored before loading. (b) BAUT should never be over loaded. (c) Load and troops to be equally distributed on both sides. (d) All items of the guns to be loaded on the same BAUT. (e) All troops should wear live jacket. (f) Anklet, boot laces to be left open and pouches to be worn upside down. 17. To carry one MMG section one BAUT is required. Load Table for one BAUT is as given below. RESTRICTED  RESTRICTED 46 S No Items Qty Weight (kg) 1. MMG with tripod 02 56.000 2. Sight unit 102 A/B 02 13.500 3. Aiming Lamp 02 9.000 4. Aiming Post 02 2.700 5. Belt Box 52 468.000 6. Shovel 02 3.600 7. Pickaxe 02 7.200 8. Net Camouflage 02 12.600 9. Section Persons 07 700.000 10. Crew 02 200.000 11. Bill hook 01 2.700 12. Spare Parts wallet 02 2.000 13. Sand Bags 100 20.800 Total 1497.300 18. To ensure that the load is properly put across the river, the BAUT should be properly sailed and proper waterman ship training should be conducted in advance. Conclusion 19. The Load Tables given in this lesson are only suggestions and necessary changes can be made as per requirement/operation scenario.  General Data of BAUTBoat Assault Universal Type IA is made of aluminium. The dimensions of the BAUT are as under o Weight - 200 kg o Length - 5.2 m o Width - 2.1 m o Depth - 570/510  Loading CapacityBAUT can carry 1400 kg of load or 16 men with complete battle load. At this time free boat is 310 mm. At the most 2300 kg of weight can be carried and at this time free boat remains at 200 mm. Two BAUTs can be joined together to carry car, Jeep and the free boat at that time remains 300 mm.  Items Issued along with BAUT Oars 08 (4 ft) Boat hook 01 (11 ft 7.5 inch) Live jacket As per requirement Spike braiding 01 Choke reel 01 Baller 01  One OBM (out board motor) bracket is attached with the BAUT on which 8.9 HP OBM is attached. Its weight is 34 kg. To lift the BAUT and to carry it from one place to another six men are required. RESTRICTED  RESTRICTED 47 GEN-6 DANGER AREA TEMPLATE FOR 7.62 mm AMMUNITION Introduction 1. The real test of soldier lies in his ability to engage target effectively on the battle field. A soldier is required to be trained during peace time under simulated battlefield environment for which field firing ranges are sited and required. Since such training is necessarily carried out during peace time, the safety of men, material and civilian property must be ensured. 2. There shall be numerous occasions where we shall be called upon to conduct firing of 7.62 mm MMG and plan exercises during field firing. Hence it is important to know the Danger Area Template of this weapon and its application on a given field firing area. Aim 3. To teach the construction of Danger Area Template for 7.62 mm ammunition. Parts 4. The lecture will be conducted in two parts:- (a) Part -I- Definitions and principles of Template design. (b) Part-II- Construction of Danger Area Template for 7.62 mm ammunition. Part-I : Definitions and Principles of Template Design Definitions 5. Danger Area. It is defined as that area of land or water together with unconfined specified air volume above them, within which danger to life, limb and property may be expected to occur, arising from the initiation of specified ammunition or explosives of ordnance nature. Each danger area has a defined danger periphery, peculiar to individual degree of hazard under fixed initiation conditions. 6. Firing Point. This is the position on the ground/map from which firing takes place. It may take the form of a point for an individual weapon, a line for a number of weapons or, an area (usually rectangular) for one or more weapons firing from different positions. 7. Arc of Fire. This is the area or arc within which the firing is to be directed. RESTRICTED  RESTRICTED 48 8. Ricochet Area. It is the area beyond arc of fire within which the bullet of projectile can travel after ricochet. 9. Burst Safety Area. Applicable to ammunition which are explosive in nature. It is the area outside the ricochet area beyond which the fragments of the explosive projectile may not be expected to travel. Principles of Template Design 10. Danger Area Templates normally defines length and width in meters and angles in mils. These are generally based on a single weapon laid on a fixed line of fire. In stipulating these lengths, widths and angles consideration is given to the Ricochet factors and danger existing from blast, fragments and debris of exploding ammunition. 11. Ricochet Factors (a) A Ricochet is said to have occurred when a projectile strikes a surface and rebounds once or more than once. (b) If a projectile strikes at an angle less than 530 mils to the surface struck and does not function or disintegrate, it may ricochet up to 800 mils vertically or either side of the line or fire/sight. (c) The range at which the projectile achieves an angle of descent of 530 mils is taken as its maximum ricochet range (MRR). The weapon elevation which achieves an angle of descent of 530 mils is taken as that elevation above which a ricochet will not occur. Therefore projectiles fired at higher elevations such as mortar bombs, do not ricochet because their angles of descent are steep (greater than 530 mils). (d) The maximum range of a weapon is greater than the maximum ricochet range. It is achieved at a higher elevation. This is about 3900 m for 7.62 mm ammunition. (e) The distance and angle to which a projectile may travel laterally depends on the type of surface struck. The types of surface are as under:- (i) Hard Surface. (ii) Soft Surface. (f) The lateral ricochet distance and angles are as under:- S No Surface Distance Ricochet Angle 1. Hard 1/4 MRR or 800 m Upto 800 mils 2. Soft 1/8 MRR or 400 m Upto 530 mils RESTRICTED  RESTRICTED 49 12. Danger Heights The danger area templates are not only concerned with danger areas but also associated with danger height above ground level. These heights are dictated by either vertex height of the projectile or maximum ricochet height, whichever is greater. The danger heights are generally related to mean sea level. Thus general height above mean sea level of the range area must be taken into consideration while computing the total danger heights in relation to air traffic flight paths. The danger height for 7.62 mm ammunition is 1275 ft for hard surface and 600 ft for soft surface. Part-II : Construction of Danger Area Template for 7.62 mm Ammunition 13. Construction. Secure drawing paper to a firm working surface. Construct in the following sequence :- (a) Step-I - Human Error Angle (i) Draw a single centreline. Take this as the line of fire. (ii) From the firing point ‘A’ measure a distance to scale of 2900m along the firing line and mark it point ‘B’. (iii) At point ‘B’ draw a line of any length on either side so that line AB is perpendicular to this line at point ‘B’. (iv) From point ‘A’ and on each side of the firing line draw lines ‘AC’ and ‘AD’ at an angle of 40 mils to ‘AB’ (40 mils is the Human Error Angle). (b) Step-II - Ricochet Angles (i) Draw a line from point ‘A’ at an angle of 530 mils from line ‘AD’. Similarly draw a line at an angle of 530 mils from ‘AC’. (ii) From points ‘C’ and ‘D’ draw lines back at an angle of 800 mils, to meet the line drawn at (b) (i) above. (c) Step-III - Ricochet Boundaries (i) Draw lines ‘WX’ and ‘YZ’ parallel to ‘AD’ and at a scale distance of 400m (1/8) of MRR and 800 m (1/4) of MRR respectively from ‘AD’. (ii) Similarly draw lines ‘PQ’ and ‘RS’ parallel to ‘AC’. (d) Step-IV - Completed Template (i) Erase all construction lines to leave the seven shapes A-R-S-C-D-Z-Y-A. (ii) Lines ‘PQ’ and ‘WX’ denote the ricochet danger area for soft surface. Lines ‘RS’ and ‘YZ’ denote area for hard surface. (iii) Lines ‘AC’, ‘AB’ and ‘AD’ should be extended upto 3900 m as it is the maximum range of 7.62 mm ammunition. RESTRICTED  RESTRICTED 50 (iv) Finally check all angles and scale distance. (v) Annotate the fwg details on the DA template:- (aa) Caliber of amn. (ab) Nature of amn. (ac) Nature of Tgt (Grnd or Hard). (ad) Scale of Template. (ae) Owners Name. (af) Firing Pt (To avoid usage in reverse). (ag) QE applicable (so that the user knows that the wpn cannot be fired at QE greater than specified when using that particular DA template due to range constrains). 14. Points to be kept in Mind. The points to be kept in mind during construction of danger area template are as under:- (a) This is made for one weapon firing from one position and that too in fixed line. (b) Scale of the template will change as per the scale of a map. (c) It goes without saying that the map reading of the person making the danger area template should be good. (d) If within the range there is even one hard spot, the template will be made for hard surface. (e) When firing in an arc, it should be made from the cone of the arc. (f) Never trace a template from an old one as the old one may have shrunk or wrinkled. (g) The corners of the danger area template should remain within the range area. (h) If number of weapons are firing from different positions, then one danger area template should be made after joining the templates of all these weapons. RESTRICTED  RESTRICTED 51 DA Template With Construction Lines Final DA Template Conclusion 15. In order to keep safety of our troops and civilians in mind while conducting field firing, it is very important for us to know about the danger area templates. It is also essential to construct the templates with due care in order to have realistic range without accidents. RESTRICTED  RESTRICTED 52 MECHANICAL HANDLING RESTRICTED  RESTRICTED 53 M-1 INTRODUCTION TO THE GUN AND TRIPOD Preliminaries 1. Stores. Gun, tripod, cartridge links, drill cartridges, ground sheet and pointers. 2. Preparation. The gun should be mounted and other stores laid nearby. 3. Safety Precautions. (Instructor to Demonstrate). (a) To inspect the body and chamber, lift top cover and bring the moving parts to the rear. Lift the feed tray and inspect body and chamber, close the top cover. Let the recoil mechanism move forward slowly by controlling it after pressing the trigger. Close the ejection opening cover. (b) Whenever drill cartridges are used, check and ensure that there are no live cartridge with them. (c) Check the stores and report. Note:- Instructor should name the parts as he handles them and should not waste time trying to get the squad to learn them. They will get to know them during handling lessons later on. Conduct of Lesson 4. Aim. To introduce the gun and the tripod. 5. Parts. The lesson will be covered in two parts:- (a) Part-I - Parts of Gun (b) Part-II - Parts of Tripod RESTRICTED  RESTRICTED 54 Part- I : Parts of Gun 6. The gun be broadly divided into fwg gps:- (a) Barrel Gp. (b) Gun Body. (c) Breech block and piston extn. (d) Return spring and buffer tube. (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) (xi) (xii) (xiii) (xiv) (Xv) The Gun (sectional arrangement) (i) Flash Suppressor (ii) Foresight (iii) Gas Block (iv) Barrel (v) Carrying Handle (vi) Feed Tray (vii) Top Cover (viii) Rear Sight (ix) Buffer Tube (x) Gas Regulator (xi) Barrel Nut Catch (xii) Trigger Guard (xiii) Trigger (xiv) Pistol Grip (xv) Safety catch 7. Barrel Gp. There are two barrel authorized with a gun. The parts are as fwg:- (a) Flash suppressor. Reduces Flash while firing (b) Barrel (i) Inner lining - Stellite Liner (ii) Weight - 3.3 kilo grams (iii) Length - 68 centimeter RESTRICTED  RESTRICTED 55 (iv) Grooves - 04 Rt hand (c) Foresight. (i) Foresight blade - Available in two sizes, 11.8mm and 9.8mm, for up/ down correction while zeroing. (ii) Foresight protector (iii) Foresight housing block (iv) Allen Screw - Helps in line correction while zeroing (d) Gas Regulator Assy. This is an exhaust type gas regulator for controlling rate of fire. (i) Gas Block. Connects the barrel with the gas regulator. It has one gas vent hole to allow passage of gas from barrel to gas regulator assy, 03 x exhaust hole which are aligned with the exhaust hole of gas plug to allow escape of gases and 01x clg hole for clg the gas vent. (ii) Gas Plug. Gas from the gas block passes to the gas cylinder through the gas plug. It has 01x vent hole for incoming gas and 03x exhaust hole for escape of gases, the left over gases are passed to the gas cyl. (iii) Gas Regulator Sleeve. It moves fwd/ backward and closes/ opens the three exhaust hole of the gas block, thereby controlling the amt of gas escaping from the exhaust hole. At ‘0’ setting the exhaust holes are completely closed. (iv) Adjusting knob. To adjust the gas regulator setting (v) Split Collar (e) Carrying Handle Assy (i) Carrying Handle (ii) Actuating lug. Locks the carrying handle with barrel. RESTRICTED  RESTRICTED 56 Foresight Protector Foresight Foresight Housing Allen Screw Block Flash Suppresser Flash Suppressor and Foresight Gas Regulator Handle Stem Actuating Lug Carrying Handle RESTRICTED  RESTRICTED 57 8. Gun Body Sling Swivel Barrel Support Gas Cylinder Piston Gas cylinder (i) (ii) (iii) (iv) (v) (viii) (vii)(vi) (ix) (x) (xi) (xv)(xiv) (xii) (xx)(xix)(xviii) (xxi) (i) Bullet Guide (ii) Ejection Slot (iii) Cocking handle slide (iv) Locking cams (v) Cocking handle (vi) Locking shoulder (vii) Ejection opening cover (viii) Barrel nut catch (ix) Rear sight (x) Positional lug (xi) Safety catch (xii) Locking recess (xiii) Pistol grip (xiv) Trigger gd (xv) Trigger (xvi) Barrel bearing (xvii) Flats (xviii) Housing front (xix) Rear mounting pin (xx) Retaining pin mounting pin (xxi) Dust cover RESTRICTED  RESTRICTED 58 (a) Barrel Supporter. Supports the barrel. (b) Gas Cylinder. Piston head is inside this. (c) Barrel Nut Catch Locks the barrel with body and helps in keeping the barrel in its place during fire and in changing the barrel. (d) Bullet Guide. Directs the bullet into chamber. (e) Ejection Slot. Bullet ejected through this..(f) Cocking handle slide and cocking handle. To pull back the piston extension (g) Locking Cam & Locking Shoulder. Helps in Locking of breech Block (h) Top Cover. Feed mechanism is housed here. (Detl of feed mechanism is covered in the functioning of gun). (j) Top Cover Catch. For opening the top cover. (k) Feed Tray. Belt is kept on this. (l) Positional lug. For closing of top cover. (m) Rear Sight. For taking aim. The rear sight is graduated from 200 metres to 1800 metres. The graduations are shown by numbers and lines. Each line below the number indicates that range. The interval between two lines is 100 metres. Aperture is used either in the folded state or raised to the vertical. Range adjustments are made by moving the slide along the leaf and are indicated by the front edge of the slide when the leaf is in the folded position and by the top edge when in vertical position. (m) Rear mounting Pin. for attaching the rear end of gun to tripod. (n) Housing Front Mounting Pin. Used to attach front end gun to tripod with the help of front mtg pin RESTRICTED  RESTRICTED 59 (o) Pistol Grip. for gripping the gun for laying and firing. (p) Ejection opening Cover. Protects the inner part of the gun from accumulating dust. (q) Safety Catch. It has two positions - ‘Safe’ and ‘Fire’. (r) Trigger. Pressed for firing. (s) Trigger Guard. For protecting the trigger. (t) Retaining Pin. Holds the pistol grip in posn. 9. Breech Block and Piston Extension. The parts of Breech Block and Piston extension is as fwg. The detail function of each part will be explained in Chapter M-2. (a) Extractor. Extracts the rd from chamber. (b) Ejector. Ejects the extracted rd. (c) Actuating Stud. Activates the motion of feed mechanism. (d) Ejection Slot. Space for falling of ejected round. (e) Feed Horn. Strips the rd from link for feeding. (f) Breech Block. Closes the breech while firing. (g) Locking Lever. Helps for positive locking of breech block. (h) Locking Lever Link. Connects Locking Lever and Piston Extn and also helps in mov of locking lever. (j) Guides. Provides alignment and surface of contact during mov of breech block and piston extn assy. (k) Firing Pin. Strikes the primer of the rd. (l) Piston extension. Consists of the Piston head, Piston and piston post. It moves under the action of high pressure gas in the gas cyl. RESTRICTED  RESTRICTED 60 (i) (ii) (iii) (v) (vi) (vii) (viii) (iv) (ix) (xi) (xii) (x) (xiii) Breech Block And Piston Extension (i) Extractor (ii) Ejector (iii) Actuating stud (iv) Vent (v) Ejection slot (vi) Feed horns (vii) Breech block (viii) Locking lever link (ix) Guides (x) Firing pin (xi) Guides (xii) Locking Lever (xiii) Piston Post RESTRICTED  RESTRICTED 61 10. ReturningSpring and Recoil Buffer. (a) Recoil Buffer. To minimize the force of recoil. It has 11 x Bellywelly washer which absorbs the recoil force. (b) Returning Spring. It helps in fwd mov of breech block and piston extn. The returning spring has a telescopic rod within it. Buffer Buffer Body Body Securing Nut Guides Buffer Plate Braking Cone Bellywelly Washers Securing Catch Recoil Buffer Part-II : Tripod 11. Parts of the tripod. (a) Legs of the tripod with socket. (b) Cradle. RESTRICTED  RESTRICTED 62 Tripod Mounting Cradle with Bracket 12. Legs. The tripod legs are held in position by clutch plates and secured by clamp levers. On the bracket at the pivot point of the legs there is a direction dial. This is in mils up to 3200 right and left. It is marked in 1,000s and sub divided in 250s. The dial can be rotated freely and a pointer on the underside of the cradle indicates the angle of the gun in relation to the dial. 13. Cradle. A cradle is fitted to the bracket by a ball and socket joint. This is secured by the cradle locking lever. The cradle is buffered to absorb the recoil of the gun during firing. The gun is secured to the tripod by a front mounting pin present in the tripod. The rear mounting pin is fitted into the rear mounting seating on the gun. A deflection drum is fitted to the right rear of the cradle. It is used to obtain adjustment in direction. When the drum is pulled out, the clicking device is brought into operation. Each click is equal to two mils. There are total 98 clicks. When the drum is pushed inwards, the clicking device is taken out of operation. With the help of the deflection drum total 11 degrees of traverse can be given. Adjustment for elevation is obtained by rotating the elevation drum on the left rear of the cradle. The clamp lever must first be released. With the help of elevation drum a total of 5 degrees of elevation or depression can be given. On the left bar of cradle there is a dovetailed socket for taking the dial sight bracket. To fit the bracket, unscrew the wing nut and slide the bracket on from the rear. Ensure that it is fully forward and tighten the wing nut. RESTRICTED  RESTRICTED 63 M-2 STRIPPING AND ASSEMBLING THE GUN AND ITS MINOR PARTS 1. Aim. To teach the stripping and assembling of the gun and its minor parts. Note:- Whenever the gun is cocked the cocking handle should be left forward,with controlled release. 2. Approach (a) Gun is stripped and assembled for cleaning, for replacing broken parts, while inspecting and while handling or taking over the gun. (b) Points to be borne in mind while stripping:- (i) Parts stripped should be kept over dry and clean place and in an orderly manner. (ii) It should be ensured that no part is damaged or lost. 3. Parts. The lesson will be covered in three parts:- (a) Part-I - Stripping of the gun. (b) Part-II - Stripping and assembling of minor parts. (c) Part-III - Assembling of the gun. Part-I : Stripping of the Gun 4. (Instructor to demonstrate). After carrying out the safety precautions, follow the sequence given below. (a) Barrel Group. Cock the gun and lift the carrying handle after pressing the barrel catch. Push out the barrel now and take it out. (b) Recoil Buffer. Ensure that the recoil mechanism is forwarded. Hold the pistol grip with left hand, with the right hand hold the recoil buffer close to the gun and with the forefinger press upon the catch. Keep lifting the recoil buffer till such time it comes away from the body. RESTRICTED  RESTRICTED 64 (c) Recoil Mechanism. With the thumb of the right hand, push the rear of the return spring rod slightly forward and upward. This disengages the stud on the rod from the key shaped slot in the body and allows the return spring and rod to be withdrawn by pulling to the rear. To remove the piston and breech block, place the left hand behind the gun body and with the right hand pull the cocking handle sharply to the rear. The piston and breech block will now protrude out from the body and can be withdrawn. Push the cocking handle forward. The body, the barrel and piston are all numbered to each other. Part-II : Stripping and Assembling of Minor Parts 5. Whenever thorough cleaning has to be carried out or whenever some breakages occur, the gun is stripped further (Instructor to strip and assemble as per sequence below). 6. Removal of Firing Pin. Push the breech block to its forward position on the piston. Using the nose of a drill round, push out the link pin and remove the breech block. Withdraw the firing pin from the rear of the breech block. (i) (ii) (iii) Hold the breach block (i) in its forward position, push out the link axis pins (ii) from the piston extension and remove the breech block upward. Remove the firing pin (iii) from the breech block. Removing Breech Block and Firing Pin 7. Removing Extractor. The tool for removing the extractor is carried in the gas regulator cleaning tool kit. RESTRICTED  RESTRICTED 65 (a) Hold the breech block with the extractor upwards, lift the locking lever until it is upright. (b) Insert the first end of the tool in the recess in the extractor plunger, position the other end into the slot in the locking lever. (c) Hold the tool down freely with the thumb of the left hand and rotate the locking lever downward, thus compressing the extractor spring. Lift out the extractor and slowly case the locking lever upwards until there is no tension on the extractor spring. Remove the tool and pull out the extractor plunger and spring. Great care must be taken that the thumb does not slip from the tool otherwise the extractor will not be removed. Extractor Stripped 8. To Assemble the Extractor Spring. Replace the extractor plunger and spring, under the thin end of the tool removing extractor into the recess of the plunger, lift up the locking lever and hook the other end of the tool as for stripping. Force the locking lever down to compress the extractor spring. Insert the extractor into its seating then raise the locking lever. Remove the tool, replace it in its container and pack away into the spare parts wallet. 9. Breech Block. Check that the number on the breech block and piston tally, than insert the head of the firing pin into its recess and slide the breech block onto the firing pin, lift the link and insert the link pin. 10. Stripping of Gas Regulator. Unscrew the gas regulator anti-clockwise until it gets free. During the early parts of removal, lift the indicator over the step of the regulator sleeve. Before removing it put one hand under the regulator to prevent losing the split RESTRICTED  RESTRICTED 66 collars. Take them off and put them at safe place. Pull the plug on the regulator seating to the rear and remove it. Stripping Gas Regulator 11. Assembling the Gas Regulator. Insert the plug into the regulator seating, ensure that the flat surface is in line with its seating. Replace the split collars, fit the regulator from the front and screw fully home. Turn the regulator anti-clockwise to the number giving reliable functioning. This is normally 6 or 7 number. 12. Stripping of Trigger Group. Remove the rear mounting pin. With the working parts forward remove the retaining pin from the rear of the trigger group by pushing out the centre pin from one side and the retaining pin from the other. Remove the trigger group by pivoting the grip slightly downward. The trigger group will not be removed from the gun except for clearing after firing. 13. Assembling of Trigger Group. Check that the safety catch is at ‘F’. Insert the recess on the front of the trigger group into its seating and holding it forward, lift the rear of the group upwards. Replace the centre pin and the locking pin. Part-III : Assembling of the Gun 14. Ensure before assembling that the numbers on the piston, breech block and the gun tally. The following sequence should be followed. 15. Piston and Breech Block. To assemble the piston and breech block hold the body of the gun in the left hand and guide the piston into the lower part of the body, at the same time ensure that the breech block is held fully forward and up. Position the breech block into its guides in the upper part of the body. Press the trigger and push the piston group fully forward. Insert the plain end of the return spring assembly and ensure that the stud on the rod is correctly engaged in the slot in the body of the gun. RESTRICTED  RESTRICTED 67 16. Recoil Buffer. To assemble the recoil buffer position the forward end of the buffer into its guides in the body and press down until the catch is engaged. 17. Barrel Group. Cock the gun before assembling barrel. With the gas regulator downwards and carrying handle upwards put the barrel onto the barrel support, keeping the gun