APS Underwater Assault Rifle
Tula Arms Plant · Assault Rifle · In Service · 1975
Also known as: Avtomat Podvodny Spetsialny, Special Underwater Automatic, APS Underwater Rifle
Overview
The APS (Avtomat Podvodny Spetsialny, meaning 'Special Underwater Automatic') is a unique Soviet assault rifle designed for underwater combat by Soviet combat frogmen. Developed by Vladimir Simonov and Pyotr Serdyukov at TsNIITochMash and manufactured by the Tula Arms Plant, the APS was adopted in 1975 and remains the most well-known underwater firearm ever produced. The rifle fires the 5.66x39mm MPS cartridge, which uses the same case as the standard 5.45x39mm but is loaded with a 120mm-long steel dart (bolt) instead of a conventional bullet. The smoothbore barrel does not impart spin to the projectile; instead, the long dart is stabilized underwater by hydrodynamic effects and cavitation. The effective range varies dramatically with depth: approximately 30 meters at 5 meters depth, decreasing to about 11 meters at 40 meters depth due to increased water pressure. The APS features a gas-operated action with a rotating bolt, select-fire capability, a 26-round detachable box magazine, and a collapsible twin-strut wire buttstock.
Specifications
| Weight (empty) | 2460 g (86.8 oz) |
| Weight (loaded) | 3900 g (137.6 oz) |
| Overall Length | 840 mm (33.07") |
| Folded Length | 620 mm (24.41") |
| Barrel Length | 300 mm (11.81") |
| Action Type | Gas Operated |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 26 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 365 m/s (1198 fps) |
| Muzzle Energy | 1386 J (1022 ft·lbf) |
| Effective Range | 30 m (33 yd) |
| Maximum Range | 100 m (109 yd) |
| Rate of Fire | 600 rpm |
| Barrel Rifling | Smoothbore |
| Number of Grooves | 0 |
| Frame Material | Steel |
| Barrel Material | Steel |
| Stock Material | Steel |
| Finish | Phosphate |
Calibers
- 5.66x39mm MPS · primary — also known as MPS, Morskoy Patron Spetsialnyy, Special Marine Cartridge
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety Selector
- Features: Smoothbore Barrel, Rotating Bolt, Select Fire, Collapsible Wire Stock, Underwater Capable, Amphibious Operation, Dart Ammunition, Fin Stabilized Projectile
Variants
- APS-5 — Modernized
- ADS Amphibious Rifle — Successor
Service history
Operators
- Soviet Naval Infantry · adopted 1975 · as APS
- Russian Naval Special Forces · adopted 1991 · as APS
- Indian Navy MARCOS · as APS
Production
Production years: 1975-present
Produced in limited quantities exclusively for Soviet and Russian naval special forces and select export customers. Exact production numbers are classified.
Origin
Country of origin: Soviet Union
Designer: Vladimir Simonov
Notes
The APS can technically be fired above water with an effective range of approximately 50 meters on land, but accuracy is poor because the smoothbore barrel provides no spin stabilization in air. Firing above water also dramatically accelerates barrel wear, reducing barrel life from approximately 2,000 rounds underwater to just 180 rounds in air. The unique 5.66x39mm MPS cartridge uses a modified 5.45x39mm case with a smokeless pyroxyline propellant charge of 1.4g, and the complete cartridge weighs approximately 27.5-28.0g due to the heavy steel dart. The MPS cartridge is also available in a tracer variant (MPST). The APS has been largely superseded by the ADS (Avtomat Dvukhsrednyj Spetsialnyj), an amphibious rifle that can effectively fire both underwater with dart ammunition and on land with standard 5.45x39mm cartridges by swapping magazines. The effective range figures listed are for underwater use at 5 meters depth; on land, effective range is approximately 50 meters.
Background
The APS was developed during the Cold War arms race to counter the growing threat of NATO combat divers and frogmen. Before the APS, underwater combat was limited to knives and spear guns. The Soviet Union's development of a fully automatic underwater firearm was considered a major tactical innovation. The long steel darts fired by the APS are sometimes described as 'underwater bullets' but function more like miniature harpoons, relying on their mass and velocity rather than fragmentation for terminal effect.