How Does a 762 Nato Pkm Feed

The light machine gun offers effective suppressive fires for the infantry squad. Typically these, like the US M249 SAW from FN (shown), use the same ammunition as the squad's riflemen.

Still master of the battlefield for well over a century, no infantry formation today would wish go into a conflict without the latest machine guns and squad automatic weapons.

Skilful employment of the machine gun and the squad automatic rifle are keys to a successful defence and attack. Their positioning and direction is a primary concern of small unit leaders at squad, platoon, and company level. Their accurate and sustained fires suppress enemy fires, neutralise opposing crew served weapons and can disrupt and defeat even a determined dismounted assault. Although well aimed shots by individual riflemen offer a valuable contribution by themselves they cannot replace the destructive power and physiological impact of the machine gun.

These weapons fall into two groups the medium or support machine guns and light machine guns (LMG) or squad automatic rifles (AR). The former are manned by a gun crew and are directed by the company commander. They support the manoeuvre and defence of the company or may be attached to a platoon where terrain dictates or a mission requires.   LMGs/ARs are organic to the squad/small unit and are integral to its tactics.

Crew Served Machine Guns

Medium machine guns (MMG) are belt fed and manned by a crew of two. They use either a bipod or, more effectively, a tripod mount with a traverse and elevation (T&E) mechanism. The T&E allows precise adjustment of fires and even provide indirect 'plunging' fires against targets in defilade using advanced gunnery. The bipod is used deploying from the march and fires from a prone position. Generally they use a mid calibre with 7.62mm most common. The crew served machine gun's sustained fire capability makes it pivotal in both the defence and attack.

The Fabrique Nationale (FN) MAG58/M240 and Russia's PK/PKM are likely the most widely used and reliable machine guns. Both are gas operated firing from an 'open bolt' for heat management in sustained firing. They feed ammunition feed from a belt located in a box or assault pack. Each has a rear stock, changeable barrel, 800-1200 meter effective range and typically employing a moderate rate of fire of 650-750 rounds per minute (rpm). The lightest M240L is 10.1kg (22.3lb) while the PKM is 7.5kg (16.53lb) without the tripod. These guns are the 'benchmark' against which future MMGs are measured.

FN's MAG 58 and the US model M240 is one of the most popular medium machine guns. This disintegrating belt fed weapon has an integral bipod and also fires from a tripod. The former is used to provide firing stability when used in a meeting engagement but the tripod offers superior accuracy in the defence and as a base of fire.

Advanced Medium Machine Guns

A number of initiatives have sought to enhance the reliability and lethality of the MMG while also reducing its weight. Sig Sauer and General Dynamics Ordnance and Tactical Systems (GD-OTS) have developed guns using a .338 calibre (8.5mm) Norma Magnum round. With greater muzzle velocity it is effective to 2,000m (further than the 7.62mm M240's 1,200m). With a terminal performance four times greater than standard 7.62mm NATO ammunition it penetrates personal body armour at longer range.

Sig Sauer unveiled its MMG in October 2018. Cory McQuilkin, product manager for Sig, shared that "the design addresses some of the long identified shortcoming of previous machine guns including being able to be feed from either the right or left and the possibility for a receiver feed cover that opens to the side rather than straight up. It can also accept a suppressor and has an adjustable gas block." The gun has 600rpm rate of fire plus at 9.09kg (20lbs) is lighter than the M240. Its modular design allows it to be converted to 7.62mm NATO if desired.

GD-OTS's Lightweight Medium Machine Gun (LWMMG) weighs less than 11kg (22lbs). Kevin Sims, senior market development director stated that "the critical factor that must be addressed in fast firing guns using high performance rounds like the .338N is mitigating recoil. LWMMG does this with our patented Short Recoil Impulse Averaging technology. It efficiently and significant reduces recoil improving target retention during firing." The effective range is over 1800m with a rate of fire of 500rpm. This allows for grazing fires, where the height of the trajectory remains close to the ground. This is a critical to delivering "final protective fires" in the defence. GD-OTS .338 also uses a specifically designed polymer case which is 20 percent lighter than metal. The gun can be used with a bipod, M192 tripod and has gun mounting points compatible with vehicle mounts.

Both Sig Sauer and GD-OTS have responded to the US Special Operations Command (SOCOM) and US Marine Corps (USMC) requirement for a new LMMG. This requirement also envisions the .338 weapon replacing some of the .50 calibre heavy machine guns as well.

Germany's Heckler & Koch, designer of the MG34 and MG42 MMG's of World War II fame, has presented the MG5 to succeed the German Army's current MG3. It retains the 7.62x51mm NATO round using disintegrating belts and firing from an open bolt.   It has selectable rates of fire of 680, 740 and 800rpm. The A2 Infantry variant with a short 460mm (18 inch) barrel weights 9.90kg (22lb) and has 1,200-1,500m reach with its soft recoil Feldafette tripod mount. Hot barrels can be changed without need for special gloves.

Russia is upgrading its infantry support weapons with production of the PKP 'Pecheneg' (designation 6P45) replacing the current PKM. Developed by the TSNIITochMMash Research Institute, the new weapon has a heavier barrel and forced-air cooling to eliminate the need to change barrels in sustained engagements. At 8.7kg it has a top carry handle, an integrated bi-pod and optical sight mounts. A belt feed 7.62×54 mm weapon it fires 650rpm. It is specifically intended for dismounted infantry use and has seen service with Russia's Internal Affairs, Spetsnaz and select army units.

Israeli Weapon Industry (IWI) developed the Negev NG7 7.62x51mm at the request of the Israeli Army. The army sought a gun with good range, lethality, suppressive capability and simplicity. NG7's firing rate of 850-1150rpm places a number rounds on target allowing a gunner to shift targets quickly. The NG7 is derived from the 5.56mm Negev light machine gun but uses only belted ammunition and has quick-detachable barrels with handles. In addition to bi-pod operation the 7.6kg gun has a tripod and is mounted on vehicles.

Israel's Negev 5.56 mm LMG draws for its medium machine 7.62 mm gun sister design (shown). The objective of Israel Weapon Industry (IWI) the developer as to provide a extremely reliable weapon for small infantry units. It differs in that it can use either a box or a magazine feed.

Light/Squad Machine Guns and Automatic Rifles

The capability of the MMG to deliver sustained fires also results in its principle drawback – higher weight. This is a concern for small units where individual mobility is critical. A gun was needed to provide high firepower but at less weight. The debate has been whether this weapon should be a light machine gun (LMG) or automatic rifle (AR). The former usually is belt-feed with a higher rate of fire while the later resembles a rifle and uses a magazine. Each has benefits and drawbacks but also often reflect different employment priorities.

FN's Minimi or M249, although referred to as a Squad Automatic Weapon (SAW), is more appropriately a light machine gun. Chambered for 5.56x54mm the 10kg (22lb) it is belt feed from a 200 round cloth pouch or plastic box. Using its bipod it effectively engages targets to 800m providing suppressing fires for squad manoeuvre. The US Army and Marines field one per fire team/section thus providing two to three SAW per squad. The M249, as with most LMGs, trades rate of fire for accuracy. The focus is on placing more rounds around a target as much to discourage the target from showing himself as to hitting him. As the SAW gunner is limited in the ammunition he can carry he usually fires in short bursts with a practical rate of fire of around 100rpm. South Korea's Daedoo K3 5.56mm LMG and Hsing-Ho's Republic of China (Taiwan) Type 75 are similar to the Minimi. The K3 is used by Korea, Thailand, Columbia, Indonesia, South Africa and the Philippines.

The belt feed LMG at the squad level has disadvantages. Since it uses belted ammunition squad members cannot exchange magazines. Second, its rate of fire tends to expend more ammunition especially used by an untrained soldier. The LMG is also of limited in house to house fighting where teams must clear buildings in close combat. A final concern is, though lighter than medium machine guns, LMGs remain heavier than the latest individual assault rifles.

IWI addresses some of these concerns in its Negev 5.56mm LMG. It is fed by either a 150 capacity belt or standard 30 or 35 round magazine and weighs 7.6kg (16.7lb). It has both semi and full automatic firing capability. Tom Alibrando, head of IWI LE sales shared that "a key requirement in the design of Negev was that it be reliable and simple to use and maintain reflecting the conscript nature of the army."   Negev has been adopted by 21 countries.

Chartered Industries (CTI) and ST Engineering Land Systems has developed its Ultimax 100. At 4.9kg (10.8lb) in the Mark 3 model it is possibly the lightest LMG fielded. Chambered for 5.56mm it uses a special 100 round drum magazine, has a modest 400-600 round rate of fire and a quick change barrel. Ultimax has exceptionally low recoil due to its 'constant recoil' design where the bolt carrier rear motion is buffered by the resistance of return springs. This facilitates accuracy and weapon control. The gun is typically fired with its bipod and has a top off-set carry handle. It is in service with fifteen armies.

The Ultimax 100 Mk8 developed by ST Engineering Land Systems is an upgraded model of its Mk5. New features include a semi-automatic fire mode and quick-change barrel. At 5kg for the basic system it is the lightest LMG.

AAI Textron has been perfecting a new approach to the LMG in its LSAT. It reduces weight by using telescoped polymer case (CT) ammunition. Wayne Pender, senior vice president Applied Technology and Advanced Programs indicated that "the advantages of the telescoped case ammunition have been demonstrated. This included the ability to reduce the squad automatic weapon weight from 17.6lb of the M249 to 9.4lb in our equivalent LSAT gun. Our work has successfully applied the CT concept to 7.62, 5.56 and 6.5mm and to combat rifles, LMGs, and MMGs."

Automatic Rifles (AR)

An alternative to the LMG are automatic rifles such as the US Browning Automatic Rifle (BAR), British Bren Gun, and Russian Degtyaryov all introduced in the 1930s but used into the 1970s.   Largely replaced in the 1980s by LMGs the Automatic Rifle is making a comeback. The US Marines have elected to replace the M249 at the squad with the H&K M27 magazine fed automatic rifle. User evaluations concluded that a more accurate but less rapid firing weapon was better suited to the fire team. An H&K spokesperson explained: "The M27 is essentially our HK416 with modifications and accessories required by the Marines. It has greater accuracy and allows the automatic rifleman to use magazines passed from other fire team members. This assures his ability to continue to provide effective fires on targets." The French Army and US Marines are also adopting the HK416/M27 as a standard infantry rifle which could allow any rifleman to assume the AR role.

The US Marines decided to return to the magazine fed automatic rifle as the primary weapon for the fire team Automatic Riflemen. They are acquiring the H&K HK416 which with some features requested is called the M27.

The US Army is seeking a "Next Generation Squad Weapons (NGSW)" which will also use new 6.8mm longer range ammunition. The objective an Army spokesperson shared "is to have the range and firepower of a machine gun with the precision and ergonomics of a rifle." The intent is to have and Automatic Rifle to replace the M249 and new service rifle to replace the M4. The NGWS is a fast program seeking to field new guns, new ammunition and an advanced sighting system by 2022. As of January 2019 AAI Textron Systems, FN America, General Dynamics OTS, Sig Sauer, and PCP Tactical have Army contracts to provide NGS-AR prototypes for technology evaluation. A Request for Proposal (RfP) for the NGWS that will be evaluated for production and fielding is expected to be released later in 2019.

Dominating the Battlefield

The power of well placed and properly manned and supported machine guns should not be underestimated. Even on today's 'high tech' battlefield the machine gun remains the greatest threat to dismounted manoeuvre, the key to successful defence, and the most effective facilitator in the attack. It is important to remember that the main battle tank was specifically developed in 1916 to overcome the dominance of the machine gun. In the dismounted ground battle that dominance continues.

by Stephen W. Miller

robinsonthily1970.blogspot.com

Source: https://www.asianmilitaryreview.com/2019/09/raining-lead/

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