Light machine guns
The light machine guns outperform assault rifles and submachine guns in terms of their combat capabilities, are designed to defeat the manpower at ranges of up to 800 m where their fire is of little effect. The light machine guns have the same caliber as submachine guns and assault rifles adopted for the serv ice and differ from them by their more heavy barrel, magazine capacity, availability of cartridge belt feeding, fire from bipods support. This ensures better fire accuracy and more high effective rate of fire in bursts up to 150 rounds per minutes. The overall weight of light machine guns is usually 6-14 kg and their length is nearly that of rifles. This allows light machine gun firers to act directly within squad formations. The modern light machine guns fill the niche between individual and group support weapons. The main way of firing a light machine gun is delivered from a bipod, from shoulder rest and there is also a need to fire it from the hip, from standing position and on the move.
The main shortage of a light machine gun lies in the need to combine its small size and weight with more intensive fire, low dispersion shot pattern and ammunition load as compared to an assault rifle. This problem my be addressed in various ways. The more simple and cheap way is to fit the assault rifle with bipods and magazine with increased number of cartridges (Israeli light machine gun «Galil» ARM, German MG.36). The second way implies the development of the light machine gun derived from a submachine gun or an assault rifle with more heavy barrel and new arrangement of controls as is the case with the Soviet RPK and RPK 47 or the Britain L86A1. In this case the infantry weapons on the level of platoon squad will be unified in terms of the cartridge and system. And at last, it is possible to develop the new design configurations. Such an approach is demonstrated in the Belgium light machine gun «MINIMI» and the Singapore «ULTIMAX 100».
Mounted and general purpose machine guns
The mounted and general purpose machine guns are capable to defeat different fire means and enemy manpower in the open and behind light shelters at ranges of up to 1,500 m. The recoil of the weapon during the fire delivery are absorbed by the mount which leads to its steadiness and ease of operation. The steadiness, heavy detachable barrel and considerable capacity of the cartridge belt ensure the aimed firing in long bursts. The effective rate of fire is equal to 250-300 rounds per minute. The design of the mount enables users to quickly and precisely shift the fire from one target to another and deliver fire due to pre set data and to engage air targets. Naturally, this weapon is heavier than light machine guns: the machine gun installed on the tripod weighs 10-20 kg, the machine gun on a wheeled mount (old obsolete versions) weighs some 40 kg or even more. The machine gun crew usually consists of two men. The change of fire emplacement takes two or three times more as compared to a light machine gun.
The so called general purpose machine guns proved to be more promising owing to the fact that they combined the qualities of both mounted and light machine guns. The general purpose machine guns retain the fire capabilities of the mounted machine guns and enhanced ease of operation or mobility due to the light a tripod (general purpose machine gun with a mount weighs 12-25 kg) and ability to deliver fire from a bipod (weight of a machine gun mounted on a bipods weighs 7-9 kg). The fire is being delivered from the a pod at ranges of up to 800 m. The general purpose machine guns feature large capabilities to defeat hostile fire means, manpower, low flying and hovering air targets. Inasmuch as the energy of low pulse submachine gun cartridges do not permit to deliver effective fire at ranges exceeding 600 m then the general purpose machine guns chambered for rifle cartridges continue to retain solid positions in the system of infantry armaments. The «combined» nature of these machine guns enables them to be mounted (after some updating) on tanks, armored vehicles and combat transport helicopters. The Soviet PKM and Belgium MAG are considered to be the best general purpose machine guns. The attempts are being made to develop the general purpose machine guns chambered for low impulse small caliber cartridges (like the Spanish machine gun «Emily» or the Israeli «Negev». Such machine guns could be «segregated in weight category» of light machine guns. Actually, they are being used in the capacity of the light weapon of fire support in air borne and reconnaissance subversion subunits. In some armies of the world the general purpose machine guns are being used instead of the light machine guns. A number of specialists maintain that in the near future the light machine gun may «fall out» from the armament system due to enhance of the low dispersion shot pattern of assault rifles and submachine guns, from the one side, and lightening of the general purpose machine guns, from the other side. However, the light machine guns still retain their importance and their positions. The light tripods with an alternative height of the line of sight and the devices of laying angels in traverse and elevation took the upper hand among many designs of the field mounts, among other things the fire against air targets is not mandatory, if only because in a number of armies they prefer firing against air targets from special weapons.
The combat performance of the machine guns is widely enhanced by the updated sights, including optical, collimating, night and combined sights. The optical and collimator sights become more common ones for machine guns. The reduction of weight of the general purpose machine guns and enhancement of accuracy in firing from the bipods remains the most important trend in their improvement. The most important point to bear in mind is the fact that a machine gun crew have to carry the machine gun itself and ammunition load in addition to the submachine gun grenade launcher complex, hand grenades and projectiles (grenades) for the complex.
Large caliber machine guns
The large caliber machine guns are intended to engage air targets and soft skin ground targets. The Cal. 12.7-15mm allows to have in the ammunition load the powerful cartridge with armor piercing, armor piercing incendiary and other bullets. This ensures the engagement of ground targets of 15-20 mm thick at ranges of up to 800 m, and the fire means, manpower and air targets at ranges of up to 2,000 m. The effective rate of fire of the large caliber machine guns constitutes up to 100 rounds per minutes in bursts.
The large caliber machine guns eventually reinforce the fire system in all types of combat. The air defence large caliber machine guns are widely used for air defence of subunits. Such machine guns are mounted on tanks, armored personnel carriers and infantry combat vehicles. Thus, the large caliber machine guns constitute the most effective type of small arms in terms of defeat of ground and air targets and among other things it is less mobile type of weapon. Nevertheless, they still excite interest of users. This is explained by their «long range fire ability» that allows them to deliver fire against the vital pin point targets, including snipers, machine guns crew emplaced in shelters and crews of fire means and hostile air threats.
The mostly widely used in the world are two old versions that is the Cal. 12.7mm Soviet DShK and the American M2HB «Browning» (chambered for a less powerful cartridge). The ease of operation or mobility of the large caliber machine guns is restricted by their large size and weight. These machine guns are installed on the universal or special (ground or air defence mounts) field mounts. The large caliber machine guns with the universal mounts weigh 140-160 kg and with the light ground mount weigh 40-55 kg. However, the advent of the more lightened large caliber machine guns, including the Russian NSV 12.7 and «KORD», the Singapore «CIS MG50» neared them to general purpose machine guns on mounts in terms of their mobility and camouflage. It should be noted here that the attempts are being made from year to year to replace the large caliber machine guns with the 20-30mm light automatic cannons. However, it is rather difficult to develop sufficiently light (with regard to the weight of the weapon, mount and the ammunition load) and mobile versions. So far, light army vehicles and light helicopters are armed with such cannons.