ASM - DT amphibious rifle The ASM - DT is a Russian folding - stock underwater firearm . It emerged in the 1990s . History and design . The introduction of the APS Underwater Assault Rifle solved the problem of how frogmen guarding a naval base could be armed , but there remained the problem of how to arm naval Spetsnaz combat frogmen when they were deployed on assault missions . These forces required a weapon able to provide them with a level of firepower that would be the same whether they were on the surface or underwater . The APS was of little use out of water , because under those conditions it was inaccurate , with an effective range of only 50 meters . In addition , when it was used out of the water , it wore out quickly — with a barrel life dropping from approx . 2000 to only 180 to 200 rounds . For this reason , the naval Spetsnaz forces often fell back on using the SPP - 1 pistol for underwater fighting , and the AK - 74 rifle for combat out of water . The commandos thought that this arrangement was unsatisfactory , and there continued to be demand for a new weapon , an underwater automatic rifle that would be as effective as an APS underwater and an AK - 74 out of water . As a result , in 1991 , at the Artillery Engineering Institute in Tula , Russia , the ASM - DT project was created , with Professor Yuriy Danilov as the rifle ' s project engineer . To meet the requirements , it had to be considered that a long smoothbore barrel was best for the new rifle to fire underwater , but a rifled barrel was necessary to gain any significant range while above water . To solve this problem and get a true ' hybrid ' design , the rifle would have to fire two different projectiles , one for underwater use , and another for above - water use . The weapon was designed with two feed slots , able to accept two magazines at the same time , in order to make the transition seamless . Professor Danilov designed the ASM - DT to fire both 5 . 45 x 39 mm 7N6 — a version of the standard Soviet ammunition , adapted to the caliber of the ASM - DT — and also 5 . 45 x 39 mm MGTS , underwater ammunition like that of the existing APS . The ASM - DT uses the same magazines as the APS while under water , and AK - 74 magazines above water . The magazine release shifts forward when using AK - 74 magazines , and the gas system automatically adjusts for firing out of water . To enable accurate shooting when outside of water , the barrel is rifled , however it has shallow grooves running along its length , which expel some gases ahead of the bullet and blow any water out of the barrel . This prevents the barrel from bursting if the rifle should need to be taken to the surface quickly , and fired outside of water without being drained first . In addition , the rifle can be equipped with a GP - 25 grenade launcher , a bayonet , or a PBS sound and flash suppressor . Additional accessories include : flame arrestor , a blank firing device for low - noise shooting ( UPMS ) , various types of optical and night sights , as well as tactical lights . The weapon has a folding stock , which , along with the pistol grip and handguard , are made of impact resistant plastic . The combat effectiveness of ASM - DT is comparable with the AK - 74 and APS when fired in air and water environments , respectively . The Russian Federation accepted the ASM - DT into service in the year 2000 . See APS amphibious rifle for considerations involving shooting power underwater .