With the rapid development of technology, new high-precision and cutting-edge weapons such as precision guided ammunition, intelligent ammunition, and electromagnetic weapons are constantly increasing, giving people a feeling of being "dazzling". Under the dazzling halo of these weapons and equipment, the development of light machine guns seems somewhat dormant. However, silence does not mean stopping, and light machine guns are also quietly changing. In March of this year, some US troops began to switch to the next generation of team weapons. The caliber of the light machine gun in the next generation of team weapons will be reduced to 6.8 millimeters. With the help of new technology, the barrel wall of the Russian RPK-16 class light machine gun is thicker and its range is longer. Many countries also have light machine guns that are both internally and externally repaired, especially by installing electronic sights such as infrared sights and laser indicators, further improving shooting accuracy. So what are the specific characteristics of the development and changes of light machine guns? Please refer to the interpretation in this issue. The light machine gun is quietly changing. The RPK-16 class light machine gun constantly pursues better firepower sustainability in the weapons industry, and many weapons and equipment have emerged to fill certain gaps. The light machine gun is one of them. Its initial appearance was to fill the firepower gap between rifles and heavy machine guns. From this perspective, the weight, range, firing rate, and hit rate of a light machine gun are all important. The performance of these aspects is closely related to both the materials used and the level of craftsmanship, as well as the design of the light machine gun. Achieving "bullets like rain" is the foundation for ensuring the power of machine guns. It can be said that exploration and practice have been ongoing since the emergence of machine guns. The continuous firing power of traditional machine guns is usually gunpowder gas, while the continuous firing power of some new machine guns also includes electricity. Taking the XM556 Minigun as an example, it is driven by a 24 volt direct current, which not only further increases the firing rate, but also reduces the weight of the gun and compresses its volume. With sufficient ammunition and continuous power supply, this machine gun can be used for close range urban operations and special operations to deal with living targets within 500 meters. The quantity and quality of ammunition directly affect the power of a light machine gun. How to carry and supply more ammunition for light machine guns is also a focus of research and development in various countries. Some European countries have proposed that in the future, new machine guns will fire buried or caseless rounds, which is largely an exploration in this regard. Compared to common machine gun bullets, the advantage of a buried head bullet is that it is lighter in weight, occupies less space, has a more regular shape, is easy to carry in large quantities, and can ensure sustained firepower. Due to the bullet being surrounded by a casing, the probability of collision between the bullet and the interior of the barrel is low, which can avoid deformation of the bullet and improve shooting accuracy. In this regard, some arms manufacturing companies in some countries have also adopted a different approach - developing composite material machine gun ammunition, such as the 6.8mm TVCM publicly displayed by a US company in 2021. Compared with machine gun shells made of metal materials, machine gun shells made of composite materials have a lighter weight, which is beneficial for reducing the battlefield burden on users. Moreover, composite material machine gun bullets can reduce the heat inside the barrel, thereby reducing the failure rate of related components and extending the service life of the machine gun. The feeding mechanism of light machine guns is also undergoing changes. Some countries pay attention to adapting light machine guns to magazines and drums of different capacities when designing. In other countries, arms manufacturing companies are continuously improving their ammunition supply methods. The Scorpio backpack feeding system designed and manufactured by the Russian Frontline Tactical Systems company can accommodate 550 7.62mm caliber machine gun rounds, effectively reducing the frequency and time required for magazine and drum replacement, allowing the machine gun to achieve sustained firepower to a certain extent. Technology empowers multiple parties to adapt to the needs of the battlefield, and for the development of weapons and equipment, battlefield needs are the guiding principle. The development of light machine guns is ultimately the result of the continuous traction of battlefield demand, and therefore presents corresponding characteristics. There have been changes in the caliber size. For light machine guns, their main business is to strike at group attacks and suppress the firepower of close range attacks. Technology is developing, and the number of protective measures against targets is also increasing and becoming stronger. In this situation, in order to effectively damage the target being struck, it is necessary to enhance the power of the light machine gun. One change brought about by this demand is that the caliber of light machine guns has increased at one point. Currently, although some countries still have 5.56mm caliber light machine guns, in more countries, 7.62mm caliber light machine guns have become the mainstay. With the increasing demand for larger range and power, some countries have begun to develop 8.6mm caliber light machine guns. In 2020, Sigsall announced that its MG338 light medium caliber machine gun had been purchased by the US Special Operations Command. This gun can fire heavier Magnum bullets with a caliber equivalent to 8.6 millimeters. With this increase in caliber and other structural adjustments, the MG338 lightweight medium caliber machine gun has a longer range and greater power. Of course, this type of light machine gun can also replace the barrel and fire 7.62mm caliber bullets, providing more options for effective target strikes. More and more modular designs are being adopted. One of the important design ideas for military research and development personnel in various countries is to flexibly assemble weapons and equipment with different shooting efficiencies like building blocks. These advantages not only enable weapons and equipment to play a more and greater role, but also reduce costs and provide further expansion space... These advantages enable modular design to enter the development process of light machine guns. The German MG5 general-purpose machine gun is representative in this regard. This gun adopts a modular design, which is endowed with flexible "transformation" ability from the source - it can be paired with different lengths of barrel, can replace different models of stock, handguard, grip, and can use different capacity ammunition chains, magazines, etc. By selecting corresponding components and accessories, MG5 machine guns can be combined to produce machine guns with different functions and powers. The light machine gun is the main combat form of the MG5, with an effective range of up to 1000 meters, which is further increased when using a heavy tripod. The gun is equipped with a long Picatinny guide rail above the barrel, which is used to install various sights. There are also small guide rails on both sides and below the air duct, which can be used to install small auxiliary kits such as front grips to improve shooting efficiency. Further move towards generalization. There is a viewpoint that generalization is an important manifestation of modular design in the use of weapons and equipment. This viewpoint has some truth, but it is not comprehensive. Experts believe that the generalization of light machine guns can be divided into two levels: one is based on modular component generalization, and these modules are used for assembly. The second refers to "one gun for multiple purposes", which means that light machine guns themselves have multiple functions and can achieve different goals by simply changing modes. However, from the current development status of light machine guns, the boundaries between these distinctions are becoming increasingly blurred, showing a trend of blending the two. The MG338 light medium caliber machine gun can be temporarily used as a sniper rifle by switching to single shot shooting mode. The FN EVOLYS light machine gun developed by FN in Belgium is also a versatile machine gun. It can not only fire like a machine gun, but also operate like a rifle, with multiple modes such as fully automatic shooting and single shot shooting; At the same time, the FN EVOLYS light machine gun can also have its barrel replaced for better targeting. The future development direction of the MG5 general-purpose machine gun is that it is getting better and better, and the light machine gun can be flexibly carried and used. One distinctive feature that distinguishes it from the heavy machine gun is its lightness. Even though some machine guns are currently labeled as general-purpose or medium caliber, their portability and ease of use still rank them among the broader category of light machine guns. The changing demands on the battlefield have led to a constant change in weight for light machine guns while improving their functionality - gaining weight, losing weight, gaining weight again, losing weight again... This "entanglement" has accompanied the entire development of light machine guns. To some extent, in order to maintain the "light" character on one's name, the development history of light machine guns is also a "weight loss and slimming history.". This "weight loss and slimming" is first reflected in material innovation. It is the active use of many new materials that has brought new vitality to light machine guns. Many light machine guns are manufactured using new materials such as engineering plastics, aluminum alloy materials, titanium alloy materials, and carbon fiber. For example, the M240L machine gun of the US military applies titanium alloy materials to components such as the receiver, which not only reduces weight but also makes the gun more sturdy and durable. The Belgian FN EVOLYS light machine gun uses a carbon fiber machine gun mount, which reduces the weight of the gun and enhances its maneuverability. The human-machine efficacy is a key concern for researchers in various countries. You should know that if a machine gun is not used smoothly, it will inevitably affect its combat effectiveness. Therefore, in recent years, new types of light machine guns introduced by various countries have made great efforts to increase the effectiveness of human-machine operations. Under this approach, reducing recoil during bullet firing, adopting multi-level adjustable buttstock, and equipping different forms of grips have all become the focus of improving human-machine performance. Many researchers in countries strive to adapt to the existing habits of users to achieve similar goals. The UK has developed the L86A1 light machine gun based on the L85A1 rifle, which has the same structural principle and similar appearance. In this way, soldiers familiar with the L85A1 rifle only need a short period of training to master the skills of using the L86A1 light machine gun and improve the efficiency of combining human and gun. The Austrian AUG light machine gun is derived from the AUG assault rifle and inherits the latter's feature of having no stock. This design can be easily completed whether the user is running with a gun or shooting while lying down. Whether it is useful or not often depends on the usage environment. Currently, some special combat environments have put forward different requirements for light machine guns. For example, in the context of street warfare, it is required that the length of the light machine gun should be short and the bullet penetration should not be too strong. This demand, in turn, has led to new changes in the development of light machine guns - the functionality has begun to balance the firing of some less powerful 5.56mm caliber ammunition, such as the FN EVOLYS light machine gun, which has achieved this compatibility. The same applies to the M249 Para light machine gun designed by the US military based on the M249 light machine gun. This gun is a version developed for its airborne troops, equipped with a short barrel and a rotating retractable stock, making it more compact in structure and ensuring a certain level of power. Battlefield survivability is also important, therefore, Sigsall Company has equipped the MG338 lightweight medium caliber machine gun with a new generation of mufflers, which can effectively reduce the flames and smoke generated during shooting and improve the marksman's concealment. In short, no matter which direction the machine gun will develop in the future, the basic requirements for the MG338 light medium caliber machine gun will not change, that is, it is easy to use and can provide abundant firepower more conveniently. (Lai Xin She)