The machine gun has a diverse user base. Until now, many armed forces adhere to the philosophy of the universal machine gun. It is suitable for many applications, from the main weapons of infantry or units operating on foot, to arming vehicles, and can be operated by any soldier. However, as attractive as this idea may be, there have been many new developments and improvements in recent decades. The main focus has been and continues to be on reducing weight and increasing caliber.
The current trend is to create light, compact machine guns of more powerful calibers. Recent developments include the M60E6, the Russian RPL-7, the HK421, the IWI Negev-7, and the newest MK3 variant, the FN Minimi 762. FN has even created a category of ultralight machine guns with its Evolys family. It doesn't even have a quick barrel change feature to save weight. In addition, attention inevitably turns to the US Army's NGSW program .
In 2025, the SIG LMG-6.8 was officially introduced under the designation M250 in a new caliber of 6.8mm x 51. This weapon weighs one and a half kilograms less than its predecessor, the M249 (also known as the FN Minimi), and increases its penetration ability due to the speed of the bullet.
The Army has also launched the Future Medium Machine Gun (FMMG) project. This machine gun is designed to replace the M240 universal machine gun, also known as the FN Browning MAG. The US Special Operations Command is currently looking for a medium-caliber machine gun. The project is called the Lightweight Machine Gun Medium (LMG-M) and is designed to fill the gap between the 7.62 NATO and cartridges.50 BMG.
Currently used by armed forces around the world, long–barreled weapons, including most machine guns, still primarily fire six types of ammunition: 7.62mm x 51 NATO, 5.56mm x 45 NATO, 7.62mm x 54 P, 7.62mm x 39, 5.45 mm x 39 and – largely ignored in Europe - 5.8mm x 42, standard ammunition of the People's Liberation Army of China.
In recent years, the range of ammunition for machine guns has expanded significantly. Naturally, attempts were made to develop promising cartridges from the rifle sector, especially cartridges of intermediate calibers. However, most of these attempts remained at the prototype or demonstration stage. The situation was different – similar to the situation in the field of sniper rifles – with new, more powerful charges. These include the NGSW family of cartridges with hybrid cartridges mentioned above, which is currently being implemented by the US Army in the form of a 6.8mm x 51.
As already mentioned, the US Army is also starting to standardize according to NATO. The developer of cartridges with hybrid cartridges, SIG Sauer, also wants to offer this technology for other NATO cartridges. It should increase the speed, range, and therefore firepower without changing the caliber. A lot is happening in the category of calibers above 7.62. Currently the patron .The 338 Norma Magnum (8.6 mm x 63) is being approved in a new category of medium–caliber machine guns - at least the Ohio Ordnance with the REAPR model, SIG Sauer with the SIG MG338 and True Velocity with the RM338 compete for the LMG-M title. On this side of the Atlantic, the Czech manufacturer FK Brno has also introduced a medium–caliber heavy machine gun in this caliber, the BKS.
With the return to traditional combat operations, the aspect of air defense has regained importance, as it now includes protection against widespread drones. In this context, the proven multi-barrel Gatling gun Dillon M134D attracted additional attention as a medium machine gun with a high rate of fire.
Ultralight and light machine guns
- Caliber: 7.62 mm x 51
- Ammunition supply: Collapsible belt; belt pouches with 50 rounds
- Length (min/max), mm: 925 / 1025
- Barrel length, mm: 406 (16 inches)
- Weight, g.: 6200
- Firing mode (rate of fire): Semi-automatic and fully automatic fire; 750 rounds/min.
- Effective firing range, m: 1000
- Operating principle: Short-stroke gas piston system.
Heckler & Koch HK421
- Caliber: 7.62 mm x 51
- Ammunition Supply: Collapsible tape
- Length (min/max), mm: 330 mm: 810/958; 419 mm : 895/1043
- Barrel length, mm: 330 mm (13 inches) / 419 mm (16.5 inches)
- Weight, g.: 330 mm: 8300 / 8500; 419 mm: 8500 / 8700
- Firing mode (rate of fire): Fully automatic fire: 670 or 700 rpm (gas adjustment)
- Effective firing range, m: Accurate suppressive fire up to 1000 m.
- Working principle: Indirect gas operation rated voltage, open gate, locked rotating bolt.
- Caliber: 7.62 mm x 51
- Ammunition Supply: Collapsible tape
- Length (min/max), mm: 1000 max.
- Barrel length, mm: 420
- Weight, g.: 6600
- Firing mode (rate of fire): Semi-automatic and fully automatic fire; 600-750 rounds/min.
- Effective firing range, m: 600
- Working principle: Gas, Open bolt, Rotating bolt
SIG Sauer M250
- Caliber: 6.8mm x 51
- Ammunition Supply: Collapsible tape
- Length (min/max), mm: 1063 max.
- Barrel length, mm: 444
- Weight, g.: 5900
- Firing mode (rate of fire): Semi-automatic and fully automatic fire; 800 rounds/min.
- Effective firing range, m: 600-800
- Working principle: Gas, Open bolt, Rotating bolt
The US Army has equipped the M1 Abrams main battle tank with it as an anti–aircraft machine gun, complete with a container for 3,000 rounds. At the Enforce Tac 2025 exhibition, Dillon Europe, in collaboration with DES Defense and IEA MilOptic, presented the Manul cUAV compact anti-drone vehicle. The all-terrain vehicle is equipped with an M134D silent machine gun, capable of firing new Urban Drone Defense ammunition from RWS. It also carries MBDA's light anti-tank guided missiles Enforcer.
Taking into account the latest developments, namely the FN Evolis, the NGSW project of the US Army and the medium-sized light machine gun project of the US Special Operations Command, six categories of machine guns can now be conditionally distinguished.:
- Ultralight machine guns weigh less than 6.5 kg, mainly due to new production technologies or the abandonment of classic design features such as rapid barrel change. They are also available in caliber from 5 to 8 mm inclusive.
- Light machine guns weigh between 6.5 and 9 kg and can usually be carried and used by a single soldier. Their caliber ranges from 5 to 8 mm inclusive.
- Medium machine guns are classic standard and universal machine guns with a caliber from 7 to 8 mm inclusive, weighing from 8 to 12 kg. They are served by one or two soldiers.
- Medium–caliber heavy machine guns are the second new category after ultralight machine guns. They use ammunition with a caliber from 8 to 10 mm and their weight is more than 9 kg.
- Heavy and superheavy machine guns have a caliber from 10 mm to 20 mm, which makes them the last category before automatic guns and grenade launchers. As a rule, these are collective weapons. This means that they are not part of the "soldier's system" in the strict sense of the word.
- Gatling guns and multi-barrel machine guns belong to the category of heavy machine guns by weight. Modern common designs use smaller caliber cartridges. However, there is a tendency to increase range and efficiency due to options with larger calibers. For example, Dillon offers the 503D model, a chambered multi-barrel weapon.50 BMG.
The machine gun remains a key element of infantry combat power.
Medium-caliber machine guns
SIG Sauer SIG-MG338
- Caliber: .338 Norma Magnum (8.6mm x 63); also 7.62mm x 51, 6.8mm x 51 and SIG.338 Norma Magnum high-pressure ammunition
- Ammunition Supply: Collapsible tape
- Length, mm: 1300
- Barrel length, mm: 610 (shorter is possible)
- Weight, g.: 9700
- Firing mode (rate of fire): Semi-automatic and fully automatic fire
- Effective firing range, m: up to 1900
- Principle of operation: A gas discharge device with a recoil reduction system
Ohio Ordnance REAPR
- Caliber: .338 Norma Magnum (8.6mm x 63); also 7.62 mm x 51
- Ammunition Supply: Collapsible tape
- Length, mm: 1384 max.
- Barrel length, mm: 624 (shorter is possible)
- Weight, g.: 12156
- Firing mode (rate of fire): Semi-automatic, 500-650 rpm.
- Effective firing range, m: more than 1,500
- Principle of operation: Recoil reduction drive with delayed action roller system
FK BRNO BKS338
- Caliber: .338 Norma Magnum (8.6 mm x 63)
- Ammunition Supply: Belt
- Length, mm: 1275 max.
- Barrel length, mm: n/a
- Weight, g.: 11000
- Firing mode (rate of fire): Semi-automatic, 550 rpm.
- Effective firing range, m: up to 1700
- Principle of operation: A gas discharge device with a recoil reduction system
Source: Enforce Tac Magazine [...]
