Thursday, September 26, 2013

9A-91 compact assault rifle (Russia)

Caliber: 9x39 mm
Action: Gas operated, rotating bolt
Overall length: 605 mm with open butt, 383 mm with folded butt
Barrel length: ??
Weight: 2.1 kg empty
Rate of fire: 600-800 rounds per minute
Magazine capacity: 20 rounds

The 9A-91 9 mm compact assault rifle was originally developed as a part of the A91 family of compact weapons, which included versions chambered for 7.62 x 39, 5.45 x 39, 9 x 39 and 5.56 x 45 ammunition. Of those, only the 9 mm version survived and entered small-scale production at the Tula Arms Factory in 1994. Designed by the famous KBP design bureau in Tula, the 9A-91 was originally intended for an Army PDW (Personal Defense Weapon) role, but instead found some favor in the ranks of MVD and Russian police troops, as a less expensive (and somewhat more versatile) equivalent of the SR-3 "Vikhr" compact assault rifle. The 9A-91 also served as a basis for a silenced "para-sniper" weapon, the VSK-94, also chambered for 9 x 39 ammunition.

The 9A-91 rifle is a gas operated, rotating bolt weapon, which utilizes a long stroke gas piston, located above the barrel, and a rotating bolt with 4 lugs. The receiver is made from steel stampings; the forend and pistol grip are made from polymer. The steel buttstock folds up and above the receiver when not in use. The charging handle is located on the right side of bolt carrier (it was welded solid on early production guns, or can be folded up on current production guns). The safety / fire selector lever was located at the left side of the receiver on early guns, but was since relocated to the right side, to clear space for the sight mounting rail. Safety / fire selector lever has 3 positions and allows for single shots and full automatic fire. The flip-up rear sight has settings for 100 and 200 meters range, but the relatively short sight base and steep trajectory of the subsonic bullet effectively restricts the 9A9-1 to ranges of about 100 meters, at which the 9 x 39 ammunition is clearly superior in penetration and hitting power to either 9mm pistol ammunition from submachine guns, or 5.45 and 5.56 mm ammunition from compact assault rifles like AKS-74U or HK-53. To aid aiming, current production 9A-91 rifles are fitted with mounting rail on the left side of receiver, which allows instalation of mounts with day (telescope or red-dot) or night (IR) sights.

SR-3 / SR-3M "Vikhr" compact assault rifle (Russia)

Caliber: 9x39 SP-5, SP-6
Action: Gas operated, rotating bolt
Overall length (butt folded / open): 396 / 640 mm, 410 / 675 mm, 700 / 970 mm with silencer
Barrel length: 156 mm, 156 mm
Weight: 2.0 kg less magazine, 2.2 kg less magazine, 3.2 kg with empty 30-rd magazine and silencer
Rate of fire: 900 rounds per minute, 900 rounds per minute  
Magazine capacity: 10 or 20 rounds, 10, 20 or 30 rounds

The SR-3 "Vikhr" ("Whirlwind") compact assault rifle was developed in TSNIITOCHMASH by A. Borisov and V. Levchenko during early 1990s. Initially known as "MA" (Malogabaritnyj Avtomat = small-size assault rifle), it was based on the silenced 9 mm AS "Val" assault rifle, and intended for concealed carry by special VIP protection teams and State security operatives. The SR-3 is widely used by various FSO (Federal Protection Service, a VIP protection organization, which guards the President and the government of the Russian Federation) and FSB (Federal Security Service) operatives, elite Russian counter-terror teams and other specialized users in the MVD and Russian police. In terms of size and weight, the SR-3 is similar to many submachine guns, but it fires much more powerful 9x39mm ammunition, available in armor piercing (SP-6) and ball (SP-5) loadings. Thus, SR-3 is considered to be an assault rifle rather than a submachine gun.

Following the demand from users, the TSNIITOCHMASH recently developed an improved version of the SR-3, with intent to produce a more versatile weapon for Law Enforcement use. The new SR-3M (Modified) compact assault rifle features more convenient fire controls and charging handle, integral forward grip (folding), and, most important, specially developed quick-detachable silencer (sound moderator) and a standard side rail for mounting day or night optics on the left side of the receiver. Another useful accessory for the SR-3M is a new magazine with enlarged capacity (30 rounds), which also provides more reliable feeding during automatic fire.

The SR-3 features the receiver, machined from a bar of steel, and gas-operated action with long stroke piston, plus the same rotating bolt group from the AS. However, the SR-3 has no integral silencer, nor provision to mount one, and thus is much shorter than the AS. Other changes included a more compact, top-folding butt and simplified flip-up rear sight. 

The redesigned charging handle, made in the form of dual sliders above the forearm, must be grasped by thumb and index finger and then retracted to load the weapon. The trigger unit is generally the same as in the AS, but the AK-type safety is replaced by ambidextrous lever above the pistol grip. The fire mode selector is of cross-bolt, push button type and located behind the trigger, inside the trigger guard. SR-3 uses same polymer magazines for 10 or 20 rounds, as the parent AS and VSS rifles. Open sights consist of a protected front post nd a flip-up rear sight with U-notch, with settings for 100 and 200 meters range.

The SR-3M differs by having AS-style controls (safety lever, semi / auto selector switch inside the trigger guard, charging handle), improved polymer furniture, AS-style side-folding shoulder stock, quick-detach mount for proprietary silencer at the muzzle, and a side-rail for mounting of various optical equipment (Red-dot or telescope day sights, night sights).

Wednesday, September 25, 2013

AS "Val" silenced assault rifle (USSR / Russia)

Caliber: 9x39 mm (SP-5, SP-6)
Action: Gas operated, rotating bolt with 6 lugs
Length: 875 mm / 615 mm (stock open / folded)
Barrel length: 200 mm
Effective range: 400 meters
Weight: 2,96 kg empty
Magazine capacity: 10 or 20 rounds

The Special Forces, generally known as “Spetsnaz” (after the Russian term “Voiska Spetsialnogo Naznacheniya” – Special Purpose Troops), always played a key role in Soviet Military Doctrine. One of the aspects of every Special Forces is that they prefer to operate stealthily, with as little sound and flash as possible from their weapons. The first generation Spetsnaz weapons were no more than  AK and AKM rifles, fitted with quick-detachable sound suppressors, and loaded with special subsonic ammunition with heavy bullets. Apparently, this was not enough, since in the mid-1980s the development of new, more effective silenced weapons was initiated. At first, designers from TSNIITOCHMASH in the city of Klimovsk developed a special-purpose 9 mm subsoniccartridges, known as 9x39 SP-5 and SP-6, based on necked-out 7.62 x 39 case. These cartridges were fitted with heavy (about 16-17 gram) standard “ball” or armour piercing bullets, with muzzle velocities about 280-300 meters per second. 

Having the ammunition, the team at TSNIITOCHMASH, lead by P. Serdyukov, developed a family of integrally silenced 9 mm weapons, which included the VSS “Vintorez” silenced sniper rifle and the AS “Val”silenced assault rifle. Both weapons are based on the same action and integrally silencedbarrel. AS is widely used by Russian Army recon units, as well as by MVD (Internal Affairs Ministry) and FSB (Federal Security Bureau) Special Forces.

The AS is a gas operated, integrally silenced weapon. The receiver is machined from steel forging for improved strength. The long stroke gas piston is located above the barrel, and rigidly attached to the bolt carrier. The rotating bolt has six lugs and locks into the receiver. The front part of the barrel, ahead of the gas port, has several sets of holes, drilled at the bottom of the rifling grooves. These holes are used to bleed some of the gun gas into the integral silencer. The trigger unit is somewhat similar to that of the Czech-made Sa. Vz.58 assault rifle, and is striker-fired. 

The safety lever is similar to the one found on all Kalashnikov-type rifles, but the fire mode selector is a separate cross-bolt type button, located within the trigger guard, just behind the trigger. The open sights are graduated up to 400 meters in 25 meter increments, but the actual effective range is about 200-300 meters due to the rainbow-shaped trajectory of the subsonic bullets. The AS is optimized for high performance armor piercing 9 x 39 ammunition, designated as SP-6, but can also fire “ball” type SP-5 ammunition, intended for VSS sniper rifles. The pistol grip and the short forearm are made from polymer, the skeletonized, side-folding butt is made from steel tubing. The AS rifle has a standard side-mounted rail for optical, night vision or red dot scopes. It has no provision for mounting a bayonet or a grenade launcher. The integral silencer could be easily detached for maintenance, repair, or compact storage, but the rifleshall not be fired with the silencer removed due to safety and reliability issues.

Groza OC-14 / OTs-14

Caliber, mm: 9x39 SP-6, 7.62x39 M43
Action: Gas operated, rotating bolt with 2 lugs
Length: 610 mm (with grenade launcher installed)
Barrel length: 240 mm
Weigth: 2.7 kg in basic configuration; 4.0 kg with attached grenade launcher
Magazine: 20rds (9mm), 30rds AK-47 type (7.62mm)
Rate of fire: 700 rounds per minute

The OTs-14 “Groza” (“thunder”) modular assault rifle was developed during the early 1990s by V. Telesh and Ju. Lebedev at the TSKIB SOO (Central Design Bureau for Sporting and Hunting Arms, located in the city of Tula). It was intended for various Special Forces in the Russian army and Internal Affairs Ministry as an dedicated CQB / Urban warfare weapon. It was briefly manufactured in small numbers at the Tula Arms factory during the mid-1990s. OTs-14 rifles saw some action during the first anti-terrorist campaign in Chechnya in 1999, but soon felt out of favor and are no longer made. 

The OTs-14 is based on the familiar AKS-74U receiver and action, modified for the larger 9 x 39 subsonic ammunition favored by various SpetsNaz troops. It is fitted into a bullpup layout, with removable trigger / pistol grip unit which could be replaced with an alternative unit integral with 40 mm grenade launcher. In the grenade-launching configuration, a single trigger controls both the 40 mm GL and the rifle itself, with a separate barrel selector. 

The safety / fire mode selector of AK pattern is retained and in bullpup configuration is especially uncomfortable to operate. The barrel can be fitted with a quick-detachable silencer. Standard open sights are built into the carrying handle, which results in relatively short sight base. The carrying handle also has mounting points for telescope, red dot or night sights.

OTs-11

Caliber: 9x39 mm SP-5, SP-6
Action: Gas operated, rotating bolt
Overall length: 490 mm (butt folded) or 730 mm (butt extended)
Barrel length: 200 mm
Weight: 2.5 kg empty
Rate of fire: rounds per minute
Magazine capacity: 20 rounds

OTs-12 "Tiss" compact assault rifle (manufacturer's index ОЦ-12 "Тисс", also sometimes spelled as OC-12 in English-language sources) was briefly manufactured during early 1990s by the TSKIB SOO (Central Design Bureau for Sporting and Hunting Arms, located in the city of Tula). It was intended for police use, and was closely based on the AKS-74U compact assault rifle, with main difference being usage of the large caliber, subsonic 9x39 ammunition, which provided significant stopping power and barrier penetration capabilities at short and medium ranges (up to 200-300 meters). Only several hundreds of OTs-12 rifles were made at TSKIB SOO in about 1993, but the mass production, which was anticipated at Tula arms factory, never commenced. Few OTs-12 rifles are still in use by some Law Enforcement units across the Russia.

The OTs-12 "Tiss" compact assault rifle by design is similar to the Kalashnikov AKS-74U rifle, featuring same gas-operated, rotary bolt action, as well as similar controls and furniture, including side-folding skeletonized buttstock. Main differences include new barrel with muzzle brake / compensator, new bolt and a new 20-round magazine for 9x39 ammunition.

Thursday, September 19, 2013

AEK-971 assault rifle (Russia)

Caliber: 5.45x39mm (AEK-971), 5.56x45 (AEK-972) and 7.62x39mm (AEK-973)
Action: Gas operated, rotating bolt, balanced
Overall length: 965 mm
Barrel length: 420 mm
Weigth: 3.3 kg without magazine
Magazine capacity: 30 rds, all standart AK-47 or AK-74 magazines depending on caliber

The AEK-971 assault rifle was developed at Kovrov Machinebuilding Plant (formerly known as Kovrov Machineguns Plant) by chief designer S.I. Koksharov. Originally designed and tested during 'Abakan' trials of late 1980s, it failed in trials, but its development was continued in hopes to sell the gun to police forces and for export. 

During early 2000s small batches of AEK-971 rifles in 5.45x39 caliber were manufactured for Russian MVD (internal affairs ministry) troops, but its production has ceased in 2006, as Kovrov Machinebuilding Plant got rid of all military production and switched to civilain products only. All plans, tools and technological packages for AEK weapons were transferred to the ZID plant in the same city, but production of the AEK-971 was not resumed due to the lack of orders that might warrant expensive tooling and production setup at new factory.

The AEK-971 assault rifle has a gas driven, balanced action with rotating bolt locking. Balancing mean that AEK971 gas drive has two gas chambers and two gas pistons. The first gas piston is linked via a gas rod to the bolt carrier and operates as usual. The second gas piston is linked to a balancing steel weight and moves in the opposite direction to the main gas piston. Both pistons are synchronized through a simple gear. This design is intended to eliminate three of the four elements of action impulses, which cause a rifle to move during full-auto fire. 

The first impulse is received when the bullet moves along the barrel - this is the basic recoil itself. The second impulse is received when the heavy bolt carrier/bolt group moves along the receiver back and forth. The third impulse is received when bolt carrier/bolt group slams against the receiver in the rear position, and the fourth when this group is stopped in the forward position after a new cartridge is chambered. The synchronous and opposite movement of the balancing weight eliminates all except the recoil impulse, so the rifle becomes far more stable during full-auto fire.

The gain in accuracy in full auto is about 15-20%, when compared to the AK-74 assault rifle in the same caliber. The AN-94 assault rifle, which was officially adopted by Russian army, has a slight edge over the AEK-971 only in short burst (2 rounds only) mode. In full-auto medium or long burst fire mode (3-5 or 7-10 rounds per burst) AEK-971 wins hands down, being also some 0.5kg lighter than the AN-94, and much simpler and cheaper to manufacture.

AEK-971 has a side-folding plastic buttstock, a plastic forearm and fire control grip, and uses standard AK/AKM or AK-74 30-round magazines (depending on the chambering). It also features a safety switch/fire mode selector of different appearance from the Kalashnikov design. The fire selector allows 3 modes of fire - single shots, 3-round bursts and full auto.

Wednesday, September 18, 2013

Nikonov AN-94

Caliber: 5.45x39 mm
Action: Gas operated, rotating bolt; moving barrel-receiver-gas drive group for delayed recoil action
Overall length: 943 mm (728 mm with butt folded)
Barrel length: 405 mm
Magazine capacity: 30 rounds
Weight, without magazine: 3.85 k g
Cyclic rate of fire:  1800 and 600 rounds per minute variable (seedescription below for explanation)
Maximum effective range: 700 meters

The AN-94 assault rifle had been officially adopted by the Russian Army and the Ministry of Internal Affairsin 1994 as a possible replacement for the venerable Kalashnikov AK-74 series assault rifles. The AN index means "Avtomat Nikonova", or Nikonov Assault rifle. This rifle had been designed by the Gennady Nikonov, a Russian arms designer, at the IZHMASH state factories, during the late 1980s and early 1990s. This rifle, initially known as the ASN prototype, had been developed for and submitted to the Russian Army trial contest, held in the early 1990s. 

This contest, known under the code name "Abakan" (a small city in Russia), was intended to develop the more effective replacement for the AK-74 assault rifles. The ASN was tested among the many other prototypes and eventually won the trials, and was consequently adopted. Originally it was intended to replace most, if not all, AK-74 rifles in the Russian service, but it soon turned out that the complete replacement is impossible due to the economical (mostly) and some other reasons. At the present time the AN-94 is considered as the "professionals' choice", and isused in limited numbers by the elite forces of the Russian Army, police and Internal Affairs Ministry. The main body of the Russian armed forces are still armed with the Kalashnikov assault rifles, and AK-type rifles will remain in service for a long time, most probably.

Much controversy is created about the AN-94 rifle, mostly because it is advertised as a quantum leap from the Kalashnikov designs, and because of its official action description, known as the "blow back shifted pulse (BBSP)". This weird description could confuse anybody, especially since it is used in conjunction with the note of gas operation of the AN-94. I will try to explain the operation of the AN-94 later in this article, but first I will discuss some of its main features.

The key improvement of the AN-94 over the AK-74 is the introduction of the 2-rounds burst mode, added to the standard single shots andfull auto mode. The two rounds bursts are fired at very high rate of fire, and a trained shooter can make a single hole in the target at 100 meters in this mode.This allows for significant increase in lethality, stopping power and body armour penetration over the single shot mode, with the same "singles hot" accuracy. The full auto mode of AN-94 consists of the two stages -first two rounds are fired in the "high rate" fire, and the remainin grounds are fired in low rate of fire, until the trigger is released or the magazine is emptied. In the single shots or the full auto mode, there's no significant advantages over the AK-74. At this point, one can ask "is all this complication of the AN-94 mechanism worth the achieved results"? Frommy point of view, there's no simple answer.

The trained professional warrior can use the 2-rounds burst capability of AN-94 to the great degree of success, but prior to this, a lot of time and resources should be spent to train this professional soldier to use AN-94 effectively. Unlike the more common designs, like the Russian Kalashnikov or American M16 rifles and others, the AN-94 internals are not "user friendly", and it took weeks, if not months, to get used to this rifle, its assembly / disassembly and maintenance procedures. It is also more expensive to made and maintain, than the AK-74. From all this it is obvious why this very interesting rifle hardly will see any widespread service, at least with the Russian Army (which at this moment is conscripted by the large, and on a low budget). On the other hand, some elite units can make a good use for major advantages of the AN-94.

From the personal, but trustworthy reports I can add the following. First, the ergonomics of the AN-94 is not the best one. The shape of the pistol grip, and the inclined from the vertical plane magazine are way from being comfortable. The rear diopter sight has small apertures, not protected from dirt, and is hard to clean in the battle conditions. It also has sharp edges and can snag in the clothes or make a scratches on the skin when handled roughly. The grenade launcher mount under the barrel is a little weird, since it uses a large "bridge" between the stock and the launcher. The folding butt interferes with the trigger when folded, and the fire selector, which is separated from the safety, is hard to operate, especially when wet. On the other hand, as said above, in the 2-rounds burst it is very accurate and offers a great advantage in the terminal effectiveness over the standard single shot mode.

Technical description of the AN-94 assault rifle.

The heart of the AN-94 is the more or less common gas operated, rotating bolt, long piston stroke action. The barrel with the gas chamber above it is mounted on the receiver, which holds the reciprocating bolt carrier with relatively short rotating bolt. The receiver is allowed to recoil inside the plastic gun shell or housing, against the receiver recoil spring. This spring is located under the receiver, at the bottom of the housing and to the left, and because of this the magazine is offset and inclined from vertical to the right. The rod under the barrel, which looks like the gas tube, is, in fact, a forward guide for the recoiling barrel / receiver assembly. This rod also used as a forward mounting point for the grenade launcher. The cocking handle is attached directly to the right side of the bolt carrier.

The feed system is quite unconventional, since it had to transfer the rounds from stationary magazine and into the recoiling receiver. To achieve this, AN-94 uses a two-stage feed, that comprises a feedway, built into the bottom of the recoiling receiver, and a separate rammer, that is used to feed the cartridges from the magazine and into the feedway.

In brief, the AN-94 works as follows. First, let's assume that the full magazine is inserted and the chamber is empty, receiver / barrel assembly is in the forward position. When one pulls the charging handle, the bolt carrier goes back, unlocking and retracting the bolt. At the same time, the rammer, which is linked to the bolt carrier via the thin steel cable and a large pulley, goes forward, stripping the first round from the magazine and placing it into the feedway in the receiver. Another action that takes the place the same time is the cocking of the hammer, which is also located in the recoiling receiver. When the charging handle is released, the bolt assembly goes forward, slamming the cartridge from the feedway and into the chamber, and locks the barrel. Now, the gun is ready to fire.

When fire selector is placed to the "full auto" mode, and the trigger is pressed, following happens. As soon as the fired bullet passed the gas port, the traditional gas operated action begins. Since the bolt group is relatively light and the amount of the gas pressure is carefully calculated, the bolt group rapidly goes back, unlocking the barrel, extracting and ejecting the spent case. Due to the recoil impulse, the barrel receiver assembly begins to recoil inside the gun housing, compressing the recoil spring. At the same time, the cartridge rammer quickly strips the next cartridge from the magazine and introduces it into the feedway. The bolt group, under the influence of its main spring and the return buffer spring, rapidly goes forward, chambering the second round from the feedway. As soon as the bolt group locks the barrel, the hammer is released automatically, and the second shot is fired with the theoretical rate of fire of 1800 rounds per minute. At this moment the receiver is still recoiling inside the housing, and its recoil is accumulated and not yet affects the shooter and the position of the gun. When the second bullet is fired and left the barrel, the recoil cycle of the receiver / barrel group is stopped, and the hammer is held in the cocked position. At this moment the shooter feels the recoil of two fired rounds simultaneously, "shifted in time". The reloading cycle continued as described above, but the hammer is held until the recoiling unit will not be returned into the forward position. If the gun was set to the "2 rounds bursts" mode, the hammer will be held cocked until the trigger will be released and then pulled again. If the gun was set to the "burst mode", the hammer unit will switch itself automatically to the low rate of fire, and will release itself only once per complete recoil cycle. I will not describe the design and the action of the trigger system of the AN-94, since it is way too complicated to be explained in few words.


Other features of the AN-94 include: the fiberglass-reinforced polymer housing, integral with the handguards; the magazine bay that can accept standard AK-74-compatible magazines with 30 or 45 rounds capacity, as well as the newest 60-rounds four-stack box magazines. The sight system of the AN-94 is a step aside from all previous Russian assault rifles, and comprised by the protected front post, adjustable for zeroing, and the asterisk-shaped rear diopter, with 5 apertures drilled in the asterisk points. To set the distance, one must rotate the asterisk and set the desired aperture at the top of the receiver. The universal scope mounting rail is attached to the left side of the receiver as a standard. The safety and the fire selector are two separate controls. The safety is mounted inside the triggerguard, and the fire selector is a small switch above the triggerguard at the left side of the receiver. The fire selector has 3 positions, for single shots, 2-round bursts and for full-auto. Safety has 2 positions - Safe and Fire. The buttstock is made from the same high-impact plastic as the housing / stock unit and folds to the right to save the space. The strange-looking "8"-shaped muzzle attachment is a special, self-cleaning muzzle brake, which is claimed to be highly effective. It can be easily detached from the muzzle if required. The front sight base carries a rear bayonet lug on its right side, so the bayonet is mounted in the horizontal plane, to the right of the muzzle. This allows to fire the grenade launcher with the bayonet attached (which is impossible with the Kalashnikov-type rifles).

Tuesday, September 17, 2013

Kalashnikov AK-9 compact assault rifle (Russia)

Caliber: 9x39 mm SP-5, SP-6
Action: Gas operated, rotating bolt
Overall length: 465 / 705 mm; 646 / 881 mm with silencer
Barrel length: ?
Weight: 3,1 kg with empty magazine, 3.8 kg  with silencer installed
Rate of fire: ? rounds per minute
Magazine capacity: 20 rounds

The AK-9 is the most recent addition to the line of the Russian-made weapons, built for the family of the sub-sonic 9x39 ammunition, which includes SP-5 ball and SP-6 armor-piercing rounds. The AK-9, developed by the Izhevsk Machine building plant (IzhMash, the home of Kalashnikov assault rifles) is intended to compete with already established weapons such as AS silenced assault rifle and 9A-91 and SR-3M multipurpose compact assault rifles. The AK-9 is intended for use by special elements of the Russian army (recon troops) and by various Law Enforcement agencies, engaged in anti-terror, anti-drug and anti-organized crime operations.

The AK-9 is based on the so-called "hundred series" of Kalashnikov assault rifles, such as AK-104, but with certain improvements. It features same tried and proven gas operated, rotary bolt action and same "Kalashnikov-style" controls including reciprocating bolt handle, safety/fire selector lever and overall layout with side-folding polymer buttstock. 

Polymer furniture is improved with addition of the accessory Picatinny rails on the bottom of the forend, and the left side of receiver is fitted with Russian-standard scope rail. Barrel can be fitted with specially designed quick-detach silencer (sound moderator), which is especially effective with 9x39 subsonic ammunition. Magazine is made of black polymer, holds 20 rounds of ammunition and appears to be of proprietary design, not compatible with other (competing) weapons of the same caliber, which are already in service with Russian military and law enforcement.

Kalashnikov AK-107 and AK-108 assault rifle (Russia)

Caliber: 5.45x39mm (5,56x45NATO for AK108)
Action: Gas operated, rotating bolt with 2 lugs, balanced bolt-carrier/bolt group to reduce recoil jumping
Length: 943 / 700 mm
Barrel lenght: 415 mm
Sighting range,m: 1000
Weigth: 3.8 kg empty
Magazine capacity: 30 rounds
Rate of fire: 850 (900 for AK108) rounds per minute

During 1960s and 1970s Soviet gun designers tried several approaches to improve hit probability of the standard infantry rifle, when firing in bursts / full automatic mode (which is primary mode of fire for ordinary infantry troops as per Soviet and Russsian field manuals and practice). One of such approaches is known as a “balanced action”. 

First developed during late 1960s by designers Alexandrov and Paranin in Izhevsk, and by Tkachev in Klimovsk, this system used a counter-mass to compensate the recoil impulse, generated by massive bolt group, slamming against the receiver in its rearmost and forward most position during the reloading cycle. The counter-mass is linked with second gas piston and moves in opposite direction to bolt group. Synchronization is achieved using a simple rack and pinion system. In this system, only the impulse of the fired cartridge is transferred to the receiver, and through the buttstock to the shoulder of the shooter. The impulses of the heavy and fast-moving bolt group are compensated by the counter-mass, and do not affect the shooting, unlike the AK where the moving bolt group produces a lot of additional recoil and vibration. The “balanced system” was employed in the AKB rifle, developed by V.M. Kalashnikov (son of the famous Mikhail Kalashnikov) in Izhevsk, and in the AEK-971 rifle, developed in Kovrov, both unsuccessfully tested during "Abakan" trials of late 1980s.

Despite the failure of both designs in the army trials, development was continued, with intention to produce weapons superior (in full automatic fire mode) to standard AK-74 for domestic police use and export. The Izhevsk entry, initially known as AKB, evolved into the AK-107 and AK-108 rifles, which differed only by the ammunition used - AK-107 was intended for domestic use and thus chambered for 5.45x39 ammunition, while AK-108 was intended for export and thus chambered for 5.56x45 NATO ammunition. Both weapons were widely advertised through late 1990s and early 2000s, although it appears that no significant orders were ever received by the IzhMash factory.

The AK-107 assault rifle is gas operated weapon with balanced action. It employs fairy conventional rotary bolt with dual locking lugs which is operated by long-stroke gas piston located above the barrel. To provide balancing action, secont gas piston is fitted in the front of the first one. When gun is fired, main gas piston moves rearwards, operating the bolt group, while balancing piston moves in opposite direction, being synchronised to the main one via simple rack and pinion system. In all other respects the AK-107 is quite similar to the standard AK-74M assault rifle, except that AK-107 / 108 were also offered with optional 3-round burst firing capability.

In 2011 IZHMASh has displayed an improved version of the AK-107, with apparent intent to offer it as a replacement for AK-74M assault rifles. Major improvements include new top cover with integral Picatinny rail and new rear sight, which is now of aperture (diopter) type.

Thursday, September 12, 2013

Kalashnikov AK-102, AK-104, AK-105 assault rifles (Russia)

Caliber: AK-102 5.56x45 mm NATO; AK-104 7.62x39 M43; AK-105 5.45x39 M74
Action: Gas operated, rotating bolt with 2 lugs
Length, mm: overall: 824; w/folded butt 586
Barrel Length, mm: 314 
Weight, 3.0 kg empty
Magazine capacity: 30 rounds
Rate of fire: 600 rounds per minute

The AK-102,  AK-104 and AK-105 rifles are essentially similar to one another, being different only in the caliber and type of magazine used. All three are 'compact' versions of the 5.56mm AK-101, 7.62mm AK-103 and 5.45mm AK-74M, respectively. 

The main visible differences between those 'Hundredth series compact assault rifles' and earlier 5.45mm AKS-74U compact assault rifle are that 'Hundred series' rifles use somewhat longer barrels and full length gas pistons, as opposed to shorter AKS-74U, and solid, side-folding polymer stocks. In fact, other than shorter barrels with special muzzle devices (flash / blast reducers) those compact rifles are similar in details to their respective full-size variants.

Kalashnikov AK-103 assault rifle (Russia)

Caliber: 7.62x39 M43
Action: Gas operated, rotating bolt with 2 lugs
Length, mm: overall: 943; w/folded butt 700;
Barrel Length, mm: 415
Weigth: 3.4 kg empty
Magazine capacity, 30  rounds
Rate of fire: 600 rounds per minute

The Kalashnikov AK-103 assault rifle is a modification of the current Russian standard issue AK-74M rifle for older 7.62x39mm ammunition. It is primary intended forexport, although it is belived that few AK-103 are in use by various Russian special Law Enforcement groups, which prefer 7.62mm over 5.45mmfor its better stopping power. So far the biggest buyer for AK-103 assault rifles was the Venezuela, which in 2006 bought 100,000 AK-103 rifles and is sintent to purchase the manufacturing license and necessary equipment for domestic production of this weapon.

The AK-103 is technically similar to AK-74M except for caliber and magazines used; any 7.62mm AK / AKM type magazine can be used in AK-103, but rifles now are issued with new production 30-round magazines made of black polymer.

Kalashnikov AK-101 assault rifle (Russia)

Caliber: 5.56x45 mm NATO
Action: Gas operated, rotating bolt with 2 lugs
Length, mm: overall: 943; w/folded stock: 700;
Barrel lenght: 415 mm
Weight: 3.4 kg empty
Rate of fire: 600 rounds per minute
Magazine capacity: 30 rounds

The AK-101 assault rifle is an export version of the 5.45mm Kalashnikov AK-74M assault rifle. The main difference between AK-101 and AK-74M is in ammunition used - the AK-101 is chambered for 5.56x45mm NATO ammunition. Otherwise it is basically the same as the AK-74M, which is current standard issue rifle of the Russian army.

Wednesday, September 4, 2013

Kalashnikov AKS-74U (Krinkov)short assault rifle (Russia - USSR)

Caliber: 5,45x39 mm
Action: Gas operated, rotating bolt with 2 lugs
Overall length: 735 mm (490 mm with foldedbuttstock)
Barrel length: 210 mm
Magazine capacity, 30 rounds standard
Weight empty: 2,71 kg
Effective range: about 200 meters
Rate of fire: 650-735 rounds per minute

The AKS-74U short assault rifle (the "U" suffix means"Ukorochennyj" in Russian = "Shortened" in English) has been developed in the late 1970s from the  AKS-74 assault rifle. The AKS-74U was intended as a personal defense weapon for tank, gun, helicopter and other vehicle crews,and for the special operations forces, which required compact but relatively powerful individual automatic weapon. The AKS-74U has the size and effective range of a typical submachine gun, but has advantage of the general issue,assault rifle ammunition and magazines, as well as the parts interchangeability with the general issue assault rifle, the AK-74. 

Since its introduction the AKS-74U, unofficially known as a "Ksyukha" (variation of a Russian woman name) or "okurok" (cigarette stub),also had been issued to various Police and other Law Enforcement forces acres the USSR and the Post-USSR countries, including Russia. Interestingly,the AKS-74U is known in the USA as the "Krinkov" - a name, apparently devised by Afghani Mujaheddins during Soviet invasion to the Afghanistan in 1980s. The AKS-74U is somewhat popular among its users due to its compact size,which allows it to be carried in the cars and even concealed under the clothes.On the other side, its effective range of fire is greatly limited by the poor accuracy at ranges beyond 150-200 meters, while the bullet itself remains lethal at much greater ranges. The AKS-74U also known for its tendency for rapid overheating when firing in bursts. 

A special version of the AKS-74Uhad been developed for the Special Forces (Spetsnaz), which could befitted with quickly detachable silencer and a special 30mm silenced grenade launcher model BS-1 "Tishina" ("silence"). The launcher uses special HE-DPgrenades, which are launched using special blank cartridges, stored in the box magazine, contained in the launcher pistol grip.

The AKS-74U has only minor differences from the basic AKS-74 assault rifle, which will describe below. For the technical description of the AK-74 and AKS-74,please refer to the  appropriate article at this site.
AKS-74U has a severely shortened barrel, with the gas chamber moved back and appropriately cut down gas piston rod. Since the portion of the barrel after the gas port is very short, a special muzzle device was designed, which is used as a flash hider and the gas expansion chamber (to achieve reliable gas operated action). 

The front sight base is lowered, and the standard adjustable rear sight is replaced by the flip-up rear (marked for 200 and 400 meters distance), mounted on the receiver cover. The receiver cover is hinged to the receiver at the front and flips up when opened (original  AK-74 receiver cover is detachable). Otherwise the AKS-74Uis similar to the  AKS-74, it has same controls, folding buttstock,and uses same magazines. AKS-74U cannot be fitted with bayonet. Some versions had a standard side-mounted rail for the night or red-dot scopes, and are known as AKS-74UN.

Kalashnikov AK-74, AKS-74 and AK-74M assault rifles (USSR /Russia)

Caliber: 5.45x39mm
Action: Gasoperated, rotating bolt with 2 lugs
Weight, empty: 3.07 kg, 2.97 kg, 3.4 kg
Length: 940 mm, 940 / 700 mm, 942 / 704 mm
Barrel length: 415mm
Rate of fire: 600- 650 rounds per minute
Magazine capacity: 30rounds standard

The idea of the reduced caliber ammunition for military shoulder arms was played with for a very long time. Each time the technology leaped forward, the standard calibers were reduced - from the 0.45 - 0.50 inch (11.4 - 12.7mm) of the mid-1800 to the .30 of the mid-1900s. The idea of further reduction of the caliber down to 6.5 - 5.6 mm (.240 - .220 inch) was also considered in many countries since the beginning of the XX century, but it was not until the 1960s when the idea of the low impulse, small-caliber, high velocity round came up to something real. When US Army adopted the M16 rifle in the mid-1960s, everybody else eyed Americans with interest. And as soon as the idea of small caliber rifle was found worthwhile, the total rearming began.

Soviet army started the development of its own small-caliber ammunition in the early 1960s. After some years of development, a new round was created. This round featured a bottlenecked, tapered case 39mm long made of steel, loaded with slim, relatively long bullet with nominal caliber of 5.45mm (actual bullet diameter is 5.62 mm). The bullet featured a combined steel and lead core with the hollow nose, muzzle velocity from the 415mm barrel was about 900 m/s. It must be noted that the new 5.45mm ammunition featured a new case of smaller diameter (compared to 7.62x39 M43 cartridges); this allowed for lighter round and also solved the problem of loading of the 7.62mm ammunition into the 5.45mm weapon by mistake (which other wise might result in a catastrophical failure of the weapon).

As soon as the new ammunition was available and accepted by the Soviet Military, it was decided to develop a new family of small arms around this cartridge, and an official requirements for new family of small arms were issued to all development organizations in 1966. Trials of new weapons commenced in 1968, and it must be note that most rifles, submitted for trials, were of highly advanced designs, as the main goal of the new weapon was to significantly improve hits probability (compared to 7.62mm AKM rifles). Most weapons were build using so called "balanced action", in which additional mass is added to the action to counter-recoil synchronously with the bolt group, to minimize its effect on the gun stability. About the only weapon of the more or less conventional design was the entry by Kalashnikov team - this was more or less the old AKM rifle, adapted for new 5.45mm ammunition. 

Afte rextensive and torturing tests two weapons were put forward for extended troop trials - the conventional A-3 assault rifle by Kalashnikov and'balanced action' SA-006 rifle by Konstantinov. During field trials the latter was found to be much more accurate (and thus more combat-effective), especially in the hands of the average trained soldiers, while being adequately reliable. Despite that, trials commission have recommended the Kalashnikov entry for adoption, as its design was already familiar to both industry and troops, and possibility of teething problems during production and use was relatively low, compared with entirely new design by Konstantinov. New Kalashnikov rifle also was simpler in design, lighter and somewhat cheaper to manufacture.

Following the decision of trials commission, Kalashnikov 5.45mm assault rifle was officially adopted by Soviet army early in 1974 as" 5.45mm Avtomat Kalashnikova, obraztsa 1974 goda (AK-74)". Basically, it was the same old AKM weapon, adapted to smaller 5.45mm ammunition and fitted with relativelylarge muzzle brake. Another distinguishing feature was found on the buttstock, in the form of two lightening oval cuts on either side. The folding butt version, known as AKS-74, which was intended for airborne troops, also featured a new type of folding buttstock - instead of the earlier pattern of underfolding stock, found on 7.62mm AKMS rifles, the AKS-74 featured more rigid and robust side-folding metallic buttstock,which folded to the left side of the gun.

Early production guns featured polymer pistol grips and wooden buttstocks and handguards.Later in production all furniture was made from polymer The "Night"version, known as AK-74N, was manufactured with the night /IR scope rail added to the left side of the receiver. The latest variation of the AK-74 family was introduced circa 1991 and replaced in production both AK-74 and AKS-74. It was the AK-74M rifle,which is still in production and currently is a standard issue rifle ofthe Russian army. 

The AK-74M externally differs from the AK-74 of late 1980s production by having the side-folding,solid black plastic buttstock and the scope rail, mounted on the left receiver as as a standard. Some minor improvements also were made in the production process and external finish of the new rifle. AK-74M retained almost all advantages and disadvantages of the earlier Kalashnikov designs,including reliability, simplicity of operations and maintenance, and less thanideal"human engineering" and ergonomics. At the present time the AK-74M,along with earlier AK-74/AKS-74 is the standard shoulder arm of the RussianArmy.

 The plans of replacing it with the widely advertised NikonovAN-94 assault rifle were not carried out to any significant extent - theAN-94 is (and most probably will be) issued only certain "elite" units of the Russian Army, police and the Internal Affairs Ministry troops. TheAK-74 type,5.45mm assault rifles also were manufactured in the East Germany,Bulgaria,Poland and Romania. Most of these designs after the dissolution of the Warsaw Pactwere converted to the 5.56mm NATO ammunition.