Both XM-8 and XM-25 were born out of the OICW plan (an ideal weapon for individual combat), which is part of the American "Land Warrior" plan. Now that the OICW project has been filmed, the "Land Warrior" project is still in progress. Many countries have also started bidding for similar projects in 1994, including ATK, Hong Kong, Contravis and Nobel. Later, the XM29 project was put on hold indefinitely because of its serious overweight, huge volume, advanced technology, inconvenient maintenance and soaring cost. The main problem of XM29 is that the technical indicators are unrealistic, and a large number of weapons and equipment are piled up, which makes the weapons cumbersome and unusable. After XM29 dismounted, the US Army once again asked ATK Company to take the lead in redeveloping a new generation of individual weapons based on XM29. This time, the US Army became a reality, requiring ATK to separate the kinetic energy weapon module of XM29 from the Grenade module, and separate the kinetic energy weapon module, which was later the XM8 automatic rifle. XM8 is still under the responsibility of the Hong Kong company. In fact, the kinetic energy weapon modules of XM29 and XM8 are variants of G36, and their structures are basically the same as those of G36. HK Company developed and quickly took out the XM8 sample gun and participated in the bidding for the SCAR project of the US Special Command. However, XM8 exposed the problems of poor accuracy and reliability in the experiment, and then XM8 was put on hold indefinitely. The army indicated that it would not replace the M 16 series, and the special command did not adopt XM8, but equipped with FNSCAR (navy number MK 16/ 17). XM8 was shot, too. XM25 is the 25mm Grenade module and fire control module in XM29. After separation, it can be used as a special Grenade launcher. XM25 inherits most mature technologies of XM29, omits unnecessary kinetic energy weapon modules, and is smaller and lighter as a whole. Now XM25 has been equipped with troops and put on trial in Afghanistan. If the Army is satisfied with the performance, it will be officially given the number of M25 and formally equipped. Originally, the Army planned to equip XM-8 and XM-25 at the same time to replace the current M 16/M203 combination. But XM-8 can't replace M 16 series at present, and XM25 is the experimental equipment. The tactics of the US Army Infantry Squad basically revolve around the squad Grenade launcher. The machine gunner suppresses the enemy, and the machine gunner cooperates to cover the grenadier, so that the grenadier can move to a suitable position and use the gun to hang grenades to destroy the enemy. At present, the core of this tactic is the M203 gun-mounted Grenade launcher, but M203 uses a low-speed Grenade, which has poor range accuracy, and the effective attack distance to a point target is only 150 meters, and the Grenade is large and carries little. If XM-25 can replace M203, it will greatly improve the firepower of the US team. XM-25 Grenade has high muzzle velocity, low trajectory and advanced fire control system, which can achieve high hit accuracy, while 25mm Grenade is small in size, light in weight and greatly increased in carrying capacity.