10. PRESENT-DAY LIGHT WEAPONS
Before I touch the present-day light weapons, it will be appropriate to define some terms used in this text.
10.1. Gas Operation
In all automatic or semi-automatic light weapons the fundamental source of operating energy is the high-pressure gas created by the rapid combustion of the propellant charge, but the term “gas operation” is reserved for a particular type in which an opening or port is provided in the wall of the barrel. When the projectile has passed this opening some of the high-pressure gases are tapped through the port to act upon a piston for converting the pressure of the gases to thrust. This thrust is then utilised through a suitable mechanism to provide the energy necessary for performing the automatic functions. Gas operation may be of three types.
10.1.1. Long Stroke Piston
In this, the piston is attached directly to the breech block and has a stroke as long as travel of the breech block. The piston is massive and, therefore, comparatively slow-moving.
10.1.2. Short Stroke Piston
In this piston itself has a short movement (about 13 mm). It weighs less than 28 gms, and so receives an impulsive blow which rapidly accelerates it.
10.1.3. Direct Gas Action
In this, gas tapped from the barrel is led back along a tube which enters an expansion chamber formed in the bolt carrier. The carrier is driven to the rear and unlocks the bolt from the barrel.
10.1.4. Disadvantage of Gas Operation
Despite the wide use of gas operation, there are draw backs to it. Due to gases passing through the port, fouling builds up narrowing the hole and thus slowing down the rate of fire. Also barrel changing in gas-operated machine guns is not easy.
10.2. Blowback Operation
In this energy required to carry out the cycle of operation is supplied to the bolt by the backward movement of the cartridge case caused by the gas pressure. The gas pressure exerted on the base of the case drives the unlocked bolt to the rear, while the empty case pushes itself out of the chamber and is ejected from the gun. The return spring, which has absorbed energy, then drives the bolt forwards to feed a cartridge from the magazine. Simple blow back system does not give automatic fire and is used in low-powered pistols only.
10.2.1. Blowback with Advanced Primer Ignition
The bolt in this case is moving forward when the primer is struck, which destroys the forward momentum of the bolt just before it stops. This reduces back-ward acceleration of the bolt, thus necessitating a lighter block. Sten Carbine is an example of this. This system has a few drawbacks.
10.2.1.1. Gun fires from open bolt, thus there is a delay in firing after pulling the trigger.
10.2.1.2. In first cycle bolt travels forward from sear but in subsequent cycles from buffer. Thus first cartridge is chambered at a slower speed than the subsequent ones. Due to the above two characteristics accuracy of weapon is affected.
10.2.1.3. If cartridges of different characteristics are mixed, it creates difficulties, because in this system bolt is balanced with the type of the cartridge. In 1965 War with India Sten Carbine became problematic due to the above reasons.
10.2.2. Delayed Blow-back
In this system the breech-block is delayed in its backward travel while the projectile is in the barrel and there-after the residual pressure is utilized to carry out the cycle of operations. The case-head remains supported till the projectile leaves the muzzle. G-3 is one good example out of the many.
10.3. Recoil Operation
In the recoil system, provision is made for locking the bolt to the barrel and these parts are mounted in the gun body so that they can slide to the rear. When the gun is fired these parts remain locked togaher as they are thrust back by the pressure resulting from the explosion of the powder gases. There can be two types of recoil.
10.3.1. Long Recoil
It is defined as a system of operation in which energy for operating the gun mechanism is obtained from a recoil movement which is greater than the overall length of the complete cartridge. This system is generally employed in artillery range and shot guns.
10.3.2. Short Recoil
In a short recoil weapon, the bolt remains locked to the barrel for only a portion of the recoil stroke. After unlocking occurs the barrel moves with the bolt until it is stopped. By properly designing this system high rate of fire can be achieved. A good example is MG1A3P / MG3.
11. THE CURRENT SMALL ARMS (LIGHT WEAPONS)
There is a large variety of small arms currently in use. Mention of all these will make the writing so lengthy that, I am afraid, the reader may lose interest. So, I shall briefly describe only some prominent types which cover more than 80% of the earth’s surface.
11.1. The FN Light Automatic Rifle (FAL)
FAL is abbreviation of Fusil Automatique Legere, meaning Light Automatic Rifle. This weapon is gas-operated. Gas intake is controlled by means of a regulator. The breech block is mechanically locked before firing can take place and unlocking does not take place until the bullet has left the barrel. It was developed by Fabrique Nationale d’Armes de Guerre of Herstal, near Liege, Belgium. This organiztion, commonly known as FN, was founded in 1889 by a combine of Liege interests and Ludwig Loewe & Co. of Berlin. FAL is or has been in production in at least eight countries and is currently in use of thirty seven countries of the world in various versions. It was originally made for the German 7.92 mm cartridge but later it was standardized for 7.62 mm NATO ammunition. It has a cyclic rate of 650 to 700 rounds per minute. Front sight is a hooded post and rear sight an aperature graduated in 100 meter steps upto 600 meters.
11.2. Gewehr G-3, Rifle G-3
The Spanish CETME Assault Rifle which was based on the design of the German St G45(M) 7.92 mm Rifle, was modified and Rifle G-3 was produced by two German firms, Heckler & Koch and Rheinmetall. G-3 operates on delayed blowback system and has a fixed barrel and semi-rigid bolt. It is in use in about eighteen countries including Pakistan. In Pakistan it is in production since 1965. The writer of this paper has the honour of developing production of G-3 Rifle in Pakistan. Heckler & Koch has developed a number of modifications of G-3 design in various calibres. G-3 has a rate of fire of 500 to 600 rounds per minute. Front sight is a hooded post and rear sight is rotary type having one notch and three apertures marked 100 to 400 meters.
11.3. Czech. Assault Rifle Model-58
The Czechoslovakian Assault Rifle Caliber 7.62 mm, Model 58 is a gas-operated weapon having cyclic rate of 700 to 800 rounds per minute. Being light in weight, it is comparatively less stable in firing. It uses Czech copy of Soviet M1943 rimless cartridge. Unlike most weapons of this type it does not have a rotating hammer, instead, it has a linear travel hammer firing pin. Pressure on the trigger causes the sear to release the hammer and fire the cartridge. It has two sears, one for semi-automatic and the other for automatic operation. Front sight is a protected post and rear tangential leaf adjustable from 100 to 800 meters.
11.4. The Soviet 7.62 mm AKM Assault Rifle
The AKM is a modification of the Soviet AK Assault Rifle which is not only a rifle but has also replaced Soviet PPSh M1941 and PPS M1943 submachine guns. It will not be right to call it a submachine gun (though some do), because it uses normal rifle ammunition and is accurate over a long range like other rifles against submachine guns which are accurate only for a short range. The AKM is outwardly quite similar to the German MP43 and MP44 but internally is quite different. It is gas operated and fires from a closed bolt and has a rate reducer attached to the trigger mechanism. Front Sight is hooded and rear is a tangential leaf.
11.5. The 7.62 mm NATO M14 Rifle
It is a gas operated rifle currently in use of U. S. Army. Production of M-14 Rifle ceased in 1964 at which time about 1.4 million of these had been produced.
11.6. General Purpose Machine Gun (MAG)
A machine gun developed by FN, Belgium which demonstrates first class engineering ability. It is known as MAG Model 58 in Belgium and as GPMG in Britain and other countries. It is gas operated having a gas regulator with which the rate of fire can be varied from 700 to 1000 rounds per minute. It’s cycle of firing starts with open bolt. MAG, like German MG-42 and U.S. M-60, uses non-disintegrating belt which consists of 50 rounds links and a lead-in-piece. Any number of links can be connected together and with lead-in-piece for feeding to the MAG. MAG is used on bipod as light machine gun and on tripod as heavy machine gun. It is chambered for 7.62 mm NATO ammunition except for Sweden where it is used for 6.5mm Swedish ammunition. MAG is very popular machine gun. It is in use in over 25 countries of the world.
11.7. German Machine Gun MG-42
MG-42 was developed by Dr. Grunow of Grossfuss in Dobeln. It was put into service in large quantities beginning in 1942, hence the name 42. It has been produced and marketed by Rheinmetall of Duesseldorf. The MG-42 introduced the recoil operated roller locking system and unquestionably the first and quickest barrel change system yet produced. By utilizing a dual feed pawl system where-in one round is positioned while the other one is being chambered, a feeding operation was produced which gave a smooth belt movement to prevent interference with the aim of the gunner by the customary violent jerking. This system has been copied by United States of America in M-60 Machine Gun. Although MG-42, during the World War-II, fully stood the test, as well during its use in the African desert as in the snow and ice of the Russian steppes, yet it has been kept under constant study for improvements.
The Model MG1A3P, adopted by Pakistan under license from Rheinmetall, Dusseldorf, has modified housing, cocking rail, bolt catch and recoil booster providing improved recoil, better ejection of fired case, stronger cocking slide and fool-proof field stripping and assembly. These modifications, which have been employed by Rheinmetall in MG-3 (the latest model), were incorporated in the MG1A3 to make it MG1A3P by the writer of this paper.
Further, MG1A3 and even MG3 had barrel with Hard-Chrome-Plated grooved hole. Up to 30 % finished and passed barrels used to get rejected after Hard-Chrome-Plating which meant considerable effort and financial loss. This Hard-Chrome-Plating was done by a specialist company in Germany (not in Dusseldorf). Writer of this paper visited the specialist company and requested for selling the technology along with their plant, but they did not agree to divulge the technology and wanted to install and run the plating plant in Pakistan by themselves. This arrangement, apart from being uneconomical, was not strategically acceptable. So, it was decided to initially buy Hard-Chrome-Plated barrels. Useful life of barrel in endurance firing test was 6,000 rounds without Hard-Chrome-Plating, and 16,000 with Hard-Chrome-Plating.
The writer of this paper did not feel comfortable with the situation and started silently working on a design of barrel bore that could replace Hard-Chrome-Plating without decrease in useful life of barrel 16,000 rounds in Endurance Firing Test. After about 6 months, a bore was designed which had same maximum and minimum bore diameters but had no corners of grooves and landing. This design was named as “Polygon Profile”. The design was sent to Rheinmetall to get a mandrel made to that design. Barrels made with the new design mandrel were fired for endurance test and gave a useful life of 18,000+.
Consequently, Pakistan abandoned the Hard-Chrome-Plating idea and started manufacturing barrels with Polygon Profile. Writer of this paper feels pleasure to mention that the Machine Gun being used by Pakistan Armed Forces since 1970 has barrel with Polygon Profile designed by him.
In addition, MG-3 has a modified feed mechanism to enable use of integrated as well as disintegrating link belt. MG-42 is also used in tanks coaxial with the gun on the turret. It also has modified cover hinge which makes the cover stop in any inclined position when opened. This is important when using the gun in a tank. This machine gun has a rate of fire of 1000 to 1300 rounds per minute with the normal bolt and 700 to 900 rounds per minute with heavy bolt. It is used as light machine gun on bipod and as heavy machine gun on tripod. MG-42 and its variations are utilization of the finest high speed techniques for mass producing metal stampings for the finest weapon in the shortest time at the lowest cost.
11.8. The U.S Machine Gun M-60
M-60 is a general purpose machine gun suitable for firing 7.62 NATO ammunition. It is an out-come of series of experimental designs developed after World War-II. First, belt feed mechanism of German MG-42 and operating technique of German rifle FG-42 was combined into a machine gun called T-44. It was modified to Model T-52 which after considerable modifications took the shape of M-60. However, feed mechanism of MG-42 and operating mechanism of FG-42 were retained except that M-60 is only automatic while FG-42 has also single fire setting. It may be mentioned that FG-42 had a bolt system which was developed from U.S. Lewis gun used in World War-I. M-60 is a gas operated weapon with short stroke piston. It is used as light machine gun on bipod and as heavy machine gun on tripod. M-61E1 Machine Gun is a modified version of M-60. In M-60E1 barrel change has been simplified and number of parts has also been decreased. Some other modifications have also been carried out.
11.9. The Kalashnikov Machine Gun
The general purpose machine gun 7.62 mm PK/PKS was developed by former Soviet Army Master Sergeant Mikhail Kalashnikov. “PK” stands for Pulomet Kalanshnikov and ‘S’ for Stankovy. Pulomet means machine gun and Stankovy means mounted. The PK is a clever combination of the basic operating principles of Soviet assault rifle AK with some original design. Unlike earlier Soviet machine guns, the gas regulator of the PK can be adjusted with the rim of an empty cartridge case. It is, no doubt, an impressive weapon.
11.10. Universal Machine Gun, Model-68
The Czechoslovak 7.62 mm Universal Machine Gun, Model-68 was produced by Ceskoslovenska Zbrojovka plant which is famous for having produced Machine Guns ZB-60 and Bren Machine Gun. Model-68 can be used in light machine gun role as well as in heavy role. It is a gas operated weapon. As light machine gun it has a light barrel and a heavy barrel is used for heavy machine gun role.
11.11. The Patchett Submachine Gun
It was developed by G.W.Patchett in mid-forties and produced by Sterling Engineering Co. of Dagenham, Essex. Original Patchett Machine Carbine was produced in limited quantities in 1951. Later, it was modified to L2A1 then to L2A2 and ultimately to L2A3. It works on the principle of blowback and has a cyclic rate of 550 rounds per minute. As length with folded stock is about 48 cm and length of barrel is 19.8 cm, and weight about 2-3/4 Kg without bayonet. It has a 34 round box magazine. It has been adopted by Britain,
Canada and a number of other countries.
11.12. The Czech Submachine Gun, Model 23
It works on the principle of blowback and has several outstanding features. The gun has a very short overall length as compared to barrel length, the reason being that it has a hollow bolt which telescopes on the barrel. It’s magazine well is in the pistol grip which gives the magazine an extra support. It uses a 24 or 40 round box magazine. The ejection slot is normally covered and opens only to eject the fired case. Another remarkable feature is that a short pull on the trigger gives semi-automatic fire, while pulling the trigger fully gives full automatic fire. Model-23 has a wooden stock and Model-25 has a folding stock. It’s overall length with folded stock is 44.5 cm with a barrel 28.5 cm long. It has a rate of fire of 600 to 650 rounds per minute. Model-23 & 25 are made in two versions one for 9 mm parabellum ammunition and the other for 7.62 mm. These carbines have a magazine filler built into their fore-ends.
11.13. The French Model 1949 Submachine Gun
It works on blowback system and has a rate of fire of 600 rounds per minute. It has a telescopic steel stock and its length with retracted stock is 46.5 cm while length of barrel is 23 cm. The magazine folds up under the gun when not in use. This makes the weapon useful for armoured or air borne troops. To sum up Model 1949 is well made and of excellent design.
11.14. The UZI Submachine Gun
The UZI is named for Major Uziel Gal, its developer. In basic operating principles and construction the UZI is quite similar to Czech Model-23. It has a firing rate of 650 rounds per minute. UZI has two versions, one with wooden stock and the other having metal folding stock. With folded stock, its overall length is 45.5 cm and its barrel is 25.9 cm long. UZI is being marketed in Europe by FN of Belgium. It is in use of armed forces of Israel and West Germany.
UZI is a pride weapon of Israel and Western World gives all credit to Israel for its development while actually it may have been copied from Czechoslovakian Model-23 or it’s predecessor ZK-476 Submachine Gun which was produced much earlier than the creation of Israel itself.
11.15. The CAR-15 Submachine Gun
It is a member of CAR-15 system developed by Colt for United States of America and is a variation of AR-15 rifle. CAR-15 works on direct gas operation, that is, it has no piston and gas blows back directly into the bolt. CAR-15 submachine gun has a 25.4 cm long barrel and its overall length is 72.9 cm. It uses 5.56 mm ammunition.
11.16. Heavy Machine Gun 12.7 mm DShK
It is a Soviet gun chambered for 12.7 mm Soviet ammunition performance of which is almost identical to U.S. Calibre .50 cartridge. DShK is a gas operated machine gun with piston. It is used as co-axial armament of tanks and in anti-aircraft role on armoured personnel carriers and tanks. It has a wheeled ground mount which can be converted into tripod. It has a circular feed mechanism which operates like cylinder of a revolver. It is designed on easy maintenance principle.
11.17. Browning Calibre .50 Machine Gun M-2
The Caliber .50 M-2 Heavy Barrel is a ground gun in use of USA Army which works on recoil operation. It’s modification AN-M3 is an aircraft gun. F-86 Saber Jet fighters, which were very effectively used by the Pakistan Air Force during 1965 war with India, were equipped with it.
11.18. Chinese 12.7 mm Machine Gun
It is a gas operated piston type machine gun having a rate of fire over 1000 rounds per minute. It is generally used against low flying aircrafts and has an effective range of 3300 meters in anti-aircraft role. Recommended maximum elevation is + 80 and depression – 30. It has also been developed and produced in Pakistan.
11.19. Heavy Machine Gun 20mm
Heavy Machine Gun MK-20Rh-202 has been produced by Rheinmetall of Duesseldorf, West Germany for firing 20 x 139 mm cartridge in disintegrating link belt, DM1. The rate of fire is 800 to 1000 rounds per minute. It is a gas operated weapon with a rigid breech block and can be used in semi-automatic and full automatic role. This gun is in extensive use of West German armed forces and has been adopted by many NATO countries. It can be installed in a variety of mounts and different types of ammunition can be used in it.
11.19.1. Types of mounts
18.104.22.168. Single gun on tripod mount with 360 traverse.
22.214.171.124. Twin or triple or quadruple guns on self-propelled mount.
126.96.36.199. Revolving turret mount for armoured vehicles.
188.8.131.52. Aircraft mount.
184.108.40.206. Ship mount.
11.19.2. Types of ammunition used on MK-20Rh-202:
220.127.116.11. High explosive incendiary.
18.104.22.168. Armour piercing, incendiary & normal.
22.214.171.124. Break up ammunition.
126.96.36.199. Target practice, tracer and normal.