As you know, the laws of ballistics operate in a completely different way under water, since the bullet has to overcome the resistance of the liquid. In recent years, in many countries, attempts have not stopped to create an effective, modern weapon for underwater shooting, albeit without much success. So the Americans offer only a harpoon pistol that shoots with special blades.
The undisputed leadership belongs to the Tula gunsmiths from Instrument Design Bureau, who have developed a universal amphibious assault rifle for ADS special forces (two-medium special assault rifle, 5.45 mm caliber) and a cartridge for it. This weapon is effective both underwater and on land. Once on the surface, a special forces soldier, in order to continue to fire, just need to join the store with "land" cartridges. The firepower of the ADF is complemented by a detachable 40-mm grenade launcher and several special sights.
Several unique know-hows are implemented in the ADS vending machine. So, the pistol grip and trigger are located in front of the store, and all moving parts are in the butt plate, which replaces the butt, which makes the ADS more compact. The shell casings are thrown not sideways, as usual, but forward with the box closed. This scheme significantly reduces gas pollution and makes it possible to shoot from any shoulder. ADS is lightweight due to the widespread use of composite materials.
The assault rifle is designed for a rate of fire of 800 rounds per minute. The firing range at a depth of 5 meters is 25 meters, and at a depth of 20 meters, the firing range is reduced by about 5 meters.