MP-401 Start

MP-401 Start
Name	MP-401 Start
Origin	Soviet Union
Type	pneumatic submachine gun
Service	1971–present
Used by	see Users and Deployment
Designer	N. A. Korolyov
Design date	1968–1970
Manufacturer	Tula Arms Plant
Production date	1971–1992
Weight	2.1 kg
Length	560 mm
Cartridge	12.5×45mm Start (pneumatic)
Caliber	12.5 mm
Action	pneumatic blow-forward
Rate	700 rounds/min
Feed	30-round detachable magazine
Sights	adjustable iron sights

MP-401 Start The MP-401 Start is a Soviet-era pneumatic submachine gun developed during the late 1960s and introduced in 1971. It was created as a low-recoil, urban close-quarters weapon intended for internal security forces and special units in constrained environments. The design emphasized silenced operation, minimized muzzle flash, and simplified logistics through a proprietary pneumatic cartridge.

Design and Development

The MP-401 Start was conceived at the Tula Arms Plant under lead designer N. A. Korolyov and influenced by experimental work at the KBP Instrument Design Bureau and TsNIITochMash. Early prototypes were tested alongside projects at the Izhevsk Mechanical Plant and compared to small-arms concepts from the Research Institute of Steel and Alloys. The development drew on lessons from the later-stage trials of the PPSh-41 replacement programs and ballooned amid doctrinal debates at the Frunze Military Academy and the RSFSR Ministry of Defense. Design goals prioritized noise suppression similar to efforts at the Scientific Research Institute of Precision Engineering, portability like the AKS-74U considerations at the Moscow Higher Military Command School, and novel pneumatic propulsion inspired by academic research at Moscow State University and the Zhukovsky Air Force Engineering Academy. Field trials involved cadres from the Internal Troops of the Ministry of Internal Affairs, instructors from the Dzerzhinsky Division, and special operations officers attached to the KGB Border Troops. Feedback from the Soviet Border Service and the Directorate of Special Programs contributed to refinements in ergonomics, feed reliability, and safety interlocks.

Technical Specifications

Mechanically, the MP-401 Start uses a sealed pneumatic cylinder firing 12.5×45mm Start cartridges developed by the Central Ammunition Research Facility and produced under license at the Tula Cartridge Works. The action is a blow-forward pneumatic cycle with a short-stroke piston derived from experiments at the Central Aerohydrodynamics Institute; the barrel assembly employs a multi-baffle integrally suppressed design similar in principle to reductions pursued at the TsNIITochMash suppressor labs. Materials engineering incorporated alloy steels specified by the Izhevsk Armory Metallurgy Bureau and polymer composites prototyped at the All-Russian Research Institute of Plastics. Fire-control includes a three-position selector influenced by ergonomics studies at the Military Engineering Academy and adjustable sights calibrated for ranges validated at the Akhtubinsk proving grounds. Performance metrics were recorded in trials with observers from the State Commission for Weapons Trials, the Leningrad Naval Infantry, and representatives of the Ministry of Internal Affairs: cyclic rate approximately 700 rounds per minute, effective suppression to 150 meters in urban engagement scenarios, and sustained accuracy comparable to contemporaneous machine pistols evaluated by the Soviet Army Armaments Directorate.

Operational History

After adoption in 1971, the MP-401 Start entered limited service with Internal Troops detachments, KGB special-response teams, and municipal riot-control units under the Ministry of Internal Affairs. Deployments included trials in Moscow, Leningrad, Kiev, Tbilisi, and Alma-Ata; units from the Separate Operational Purpose Division and the 9th Directorate conducted specialized training at the Ryazan Guards Higher Airborne Command School and the Frunze Academy tactical centers. Internationally, the platform was demonstrated at arms exhibitions attended by delegations from the Warsaw Pact, including observers from the Polish People's Army, Nationale Volksarmee, and the Hungarian People's Army; export variants were evaluated by the Council for Mutual Economic Assistance procurement cells. During the 1980s, the MP-401 saw limited use in urban policing operations and counter-terrorism drills exemplified at the Dubrovka training ranges. With the dissolution of the Soviet Union, inventories were redistributed among successor states and retained by the Russian Federation, Belarus, Ukraine, and Kazakhstan for specialized units and training cadres.

Variants and Modifications

Variants included the MP-401N night-vision-equipped model incorporating optics supplied by the Kazan Optical-Mechanical Plant and an MP-401S short-barrel carbine that shared components with prototypes from the Izhevsk Experimental Design Bureau. A compact MP-401KP demonstrator tested collapsing stocks and ambidextrous controls inspired by modular kits produced by the Kovrov Mechanical Plant. Ammunition adaptations were pursued by the All-Russian Scientific Research Institute for Technical Physics to optimize the 12.5×45mm Start round for subsonic performance; specialized suppressor kits and accessory rails were manufactured by TOZ and the Degtyarev Plant under state factory contracts. Field-modification programs by units from the Federal Protective Service resulted in bespoke sighting solutions using optics from the Novosibirsk Instrument-Making Plant.

Users and Deployment

Primary operators included units of the Soviet Internal Troops, KGB special units, and municipal security detachments across Soviet republics such as the Russian SFSR, Ukrainian SSR, Byelorussian SSR, Kazakh SSR, Georgian SSR, and Azerbaijani SSR. Post-Soviet users encompassed the Russian Federation's FSB and National Guard, the Belarusian OMON, Ukraine's Special Tasks Patrol Police (during transitional inventories), and law-enforcement contingents in Kazakhstan and Armenia. International demonstrations prompted interest from Warsaw Pact militaries and select Non-Aligned Movement countries; however, widespread foreign procurement remained limited, with small quantities reaching police arsenals in allied states and client regimes.

Safety and Maintenance

Safety systems integrated by the original design bureau included a three-position safety and a firing-pin block tested by the State Technical Inspection Authority and certified at the Central Clinical Hospital ranges. Maintenance schedules adhered to protocols from the Tula Arms Plant manuals and the Armament Service Directorate, emphasizing cylinder seal replacement, bore inspection using tooling supplied by the Leningrad Tool Institute, and magazine-feed testing standardized at the Central Armory. Depot-level overhaul procedures were performed at repair facilities such as the Izhevsk Repair Plant and the Zagorsk Armament Works; training for armorers was conducted at the 59th Ordnance Training Center and the Main Directorate for Formation and Staffing.

Legacy and Impact

The MP-401 Start influenced later suppressed and low-signature weapon projects pursued by TsNIITochMash, KBP, and the Tula design bureaus, informing developments in compact submachine gun concepts and non-traditional propulsion research at the Moscow Institute of Physics and Technology and the Bauman Moscow State Technical University. Its use by internal security and special units shaped small-arms procurement discussions at the Ministry of Defense and the Ministry of Internal Affairs, and it remains a study case at military academies such as the Frunze Academy and the Combined Arms Academy for lessons in urban armament specialization. Category:Submachine guns