APS underwater rifle
Soviet underwater assault rifle firing a long steel bolt from a rifled barrel.
The APS underwater assault rifle—its Russian name translates to "Special Underwater Assault Rifle"—was developed by the Soviet Union in the early 1970s and officially adopted in 1975. It is manufactured at the Tula Arms Plant in Russia and exported through Rosoboronexport. Standard bullets lose accuracy and range quickly underwater, so the APS uses a 120-millimeter-long, 5.66 mm caliber steel bolt designed specifically for this environment. Its magazine holds 26 rounds. The barrel is rifled, which helps stabilize the projectile underwater; however, the weapon is somewhat inaccurate when used above water.
Compared to a speargun, the APS offers greater range and penetration. This makes it useful for engaging an opposing diver through reinforced dry suits, protective helmets (whether air-filled or not), thick components of breathing gear and harnesses, and the plastic casings or transparent covers of small underwater vehicles. It is more powerful than an underwater pistol but is bulkier, heavier, and slower to aim, especially when moving its long barrel and large flat magazine sideways through water.
**History** Growing threats from frogmen attacking naval bases led to countermeasures. In the USSR, guard divers were deployed to stop them, initially armed only with knives and AK-type rifles. Those rifles were kept in waterproof cases and could only be used on the surface, leaving the knife as the sole effective underwater weapon. The SPP-1 underwater pistol, adopted in 1971, proved useful mainly for close-quarters self-defense rather than engaging distant targets. Vladimir Simonov then took on the task of developing an underwater assault rifle. The APS was adopted in 1975, followed by lengthy improvements. One upgrade added a perforated gas pipe with a shield to break up emitted gas bubbles, making aiming easier and reducing bubble visibility for stealthier firing. In 2021, Rosoboronexport reported delivering APS rifles to a foreign country. Because the APS is ineffective outside water, the ASM-DT was later designed to address that limitation.
**Design** The APS’s initial design was based on the AK-74. Its magazine holds 26 rounds. The first development stage focused on the cartridge: a standard 5.45 mm by 39 mm cartridge was lengthened by about 115 mm to accommodate the sharp-fronted steel bolt. Another cartridge version contained a min
- field
- Underwater firearm
- nationality
- Soviet Union / Russia
- known_for
- First underwater assault rifle adopted by Soviet military
- caliber
- 5.66 mm
- magazine_capacity
- 26 rounds
- barrel
- Rifled
Quick Facts
- Origin
- Soviet Union
- Is Ranged
- Yes
- Service
- 1975–present
- Designer
- Vladimir Simonov
- Design Date
- 1970s
- Manufacturer
- Tula Arms Plant, / TsNIITochMash
- Weight
- 3.0 kg empty / 3.9 kg loaded
- Length
- 840 mm with stock extended / 620 mm with stock retracted
- Part Length
- 300 mm
- Cartridge
- 5.66×39mm MPS with 5.66×120mm steel darts and tracer MPST
- Caliber
- 5.66mm
- Action
- Gas actuated
Facts from the source article.
Lore & Background
The rising threat of attacks by frogmen in naval bases caused various anti-frogman techniques to be developed. In the USSR, guard frogmen were sent to stop the attackers, initially armed only with knives and AK-type rifles that could only be used on the surface. The SPP-1 underwater pistol was accepted in 1971 but proved useful only for close-up self-defence. Vladimir Simonov undertook the job of developing an underwater assault rifle. The APS was adopted in 1975, followed by lengthy improvement work, including fitting a perforated gas pipe with a special shield to break up emitted gas bubbles for stealthier firing.
Reader's Guide
The APS underwater rifle represents a significant step in underwater combat capability, addressing the limitations of earlier weapons like the SPP-1 pistol. Its long steel bolt, stabilized by hydrodynamic effects rather than rifling, gives it longer range and more penetrating power than spearguns, useful against reinforced dry suits, protective helmets, breathing sets, and small underwater vehicles. However, it is bulkier and heavier than a pistol, takes longer to aim, and is somewhat inaccurate when used out of water. The APS has been used by several countries including Azerbaijan, Belarus, India (by MARCOS commandos), Kazakhstan, Russia, Serbia (by the 82nd River Underwater Demolition Company), and Ukraine. Its limitations led to the design of the ASM-DT amphibious rifle. In 2021, Rosoboronexport reported delivery of APS rifles to a foreign country.
Did You Know?
- The APS fires a 120-millimetre-long, 5.66 mm calibre steel bolt.
- Its barrel is rifled; the projectile is stabilized by the rifling, not by hydrodynamic forces alone.
More in Soviet inventions 1-24
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record