ADS amphibious rifle The ADS is an assault rifle of Russian origin specially made for combat diver s . It is of a bullpup layout and is chambered in the 5 . 45x39mm M74 round . The ADS can adapt a GP - 30 type underbarrel grenade launcher and optical sight s . Early combat diver weaponry . For several decades , Soviet and then Russian combat divers and naval commando units were armed with special weapons for underwater combat , including the SPP - 1 pistol and APS underwater assault rifle . The main drawback of these weapons is that their effectiveness ( and life expectancy ) for use above the water is severely degraded compared to standard ' above water ' weapons . Therefore , combat divers and other Spetsnaz units , when engaged in amphibious operations ( below the water and above ) , had to carry on the mission two types of weapons - one for underwater use and another for use when on shore or on board of enemy surface vessels . The first known attempt to produce a single weapon which could be effectively used either below or above the water was the ASM - DT experimental ' dual - medium ' or amphibious assault rifle , developed in Tula in around 2000 . The main problem with ASM - DT was that it still had to use extremely long , specially designed underwater ammunition when submerged , which necessitated overly long receiver , complicated magazine well of adjustable size and two types of magazines . This was found unsuitable for combat use , and further development commenced at the famous arms development facility KBP ( Instrument Design Bureau ) in Tula . By 2005 , design team at KBP has successfully developed effective underwater ammunition which retains the compact size of the standard issue 5 . 45x39 7N6 ball ( as well as 7N10 and 7N22 AP ) rounds , and thus can be loaded and fired from standard AK - 74 - type box magazines , and , more importantly , fired from the same chambers and barrels that would accept the ' above - water ' 7N6 ammunition . New cartridge . This new cartridge is known as 5 . 45x39 PSP , and is externally similar to standard 5 . 45x39 ammunition except that it has a different bullet shape . Internally it differs in having a long bullet , which has specially calculated shape and protrudes back into the cartridge case all the way to the bottom , with overall bullet length being about 53mm ( 2 . 1 inch ) , compared to overall cartridge length of 57mm . There are two types of PSP ammunition , the 5 . 45 PSP ( combat ammunition ) with hardened steel projectile weighting 16 gram ( muzzle velocity on air about 330 m / s ) and 5 . 45 PSP - U ( practice / training ammunition ) with bronze projectile weighting 8 gram ( muzzle velocity on air about 430 m / s ) . Effective range with PSP ammunition varies from 25 meters at 5 meters depth to 18 meters at 20 meters depth ; effective range of the PSP - U training ammunition when below the water is about half . Rifle info . The rifle was designed by Russia ' s Tula Instrument Design Bureau . It is equipped with a 40 mm grenade launcher ( no mention is made of grenades for underwater use ) . The weight of the gun with the grenade launcher is approximately 4 . 6 kg . The weapon uses 5 . 45х39 mm bullets and fires at a firing rate of 800 shots / min with a range on land of 500 m . The weapon ' s effective underwater firing range when using the specially designed cartridge is about 25 meters at a depth of 30 meters and 18 m at a depth of 20 m ( the underwater cartridge very similar in external appearance to the standard 5 . 45x39 ammunition except for a different specially calculated bullet shape ) . The length of the bullet is 53 . 5 mm compared to an overall cartridge length of 57mm . Trials . The ADS is said to be under extensive field trials by undisclosed units of Russian Naval special forces . If adopted , it will replace APS underwater weapons and , possibly , some AK - 74M general issue assault rifles in service with Russian Navy special operation units and other Russian special forces , which might be engaged in underwater operations ( security , counter - terrorism in the sea , etc . ) .