AK-74
The AK-74 (Russian: or "Kalashnikov automatic rifle model 1974") is an assault rifle designed by Soviet small arms designer Mikhail Kalashnikov in 1974. It is chambered for the 5.45×39mm cartridge, which replaced the 7.62×39mm cartridge of Kalashnikov's earlier automatic weapons for the Soviet armed forces. The rifle first saw service with Soviet forces in the 1979 Afghanistan conflict. The head of the Afghan bureau of the Pakistani Inter-Services Intelligence claimed that the CIA paid $5,000 for the first AK-74 captured by the Afghan mujahideen during the Soviet–Afghan War. , most countries of the former  Soviet Union use the rifle. Licensed copies were produced in Bulgaria (AK-74, AKS-74 and AKS-74U), and in the former East Germany (MPi-AK-74N, MPi-AKS-74N, MPi-AKS-74NK). Design details. The AK-74 was designed by А. D. Kryakushin's group under the design supervision of Mikhail Kalashnikov. It is an adaptation of the 7.62×39mm AKM assault rifle and features several important design improvements. These improvements were primarily the result of converting the rifle to the intermediate-calibre high velocity 5.45×39mm cartridge. In fact, some early models are reported to have been converted AKMs, re-barreled to 5.45×39mm. Compared  with the preceding AKM, the AK-74 has better effective range, firing accuracy (a main development goal), and reliability. The AK-74 and AKM share an approximate 50% parts commonality (interchangeable most often are pins, springs and screws). Operating mechanism. The rifle's operation during firing and reloading is identical to that of the AKM. After ignition of the cartridge primer and propellant, rapidly expanding propellant gases are diverted into the gas cylinder above the barrel through a vent near the muzzle. The build-up of gases inside the gas cylinder drives the long-stroke piston and bolt carrier rearward and a  cam guide machined into the underside of the bolt carrier along with an ejector spur on the bolt carrier rail guide, rotates the bolt approximately 35° and unlocks it from the barrel extension via a camming pin on the bolt. The moving assembly has about of free travel which creates a delay between the initial recoil impulse of the piston and the bolt unlocking sequence, allowing gas pressures to drop to a safe level before the seal between the chamber and the bolt is broken. Like previous Kalashnikov-pattern rifles, the AK-74 does not have a gas valve; excess  gases are ventilated through a series of radial ports in the gas cylinder. Since the Kalashnikov operating system offers no primary extraction upon bolt rotation, the 5.45×39mm AK-74 bolt has a larger extractor claw than the 7.62×39mm AKM for increased extraction reliability. Other minor modifications were made to the bolt and carrier assembly. Barrel. The rifle received a new barrel with a chrome-lined bore and 4 right-hand grooves at a 200 mm (1:7.87 in) or 37 calibres rifling twist rate. The front sight base and gas block were redesigned. The gas block contains a gas channel  that is installed at a 90° angle in relation to the bore axis to reduce bullet shear at the port hole. A pair of support brackets are cast into the gas block assembly and are used to attach a BG-15c or GP-25 underslung 40 mm grenade launcher. Like the AK-47 and AKM, the muzzle is threaded for the installation of various muzzle devices such as the standard muzzle brake or a blank-firing adaptor, while a spring-loaded detent pin held in the front sight post prevents them from unscrewing while firing. However the muzzle threads have been relocated  to the front sight base for both easier and more economic replacement in case of thread damage. The distinctive standard-issue muzzle brake features a large expansion chamber, two symmetrical vertical cuts at the forward end of the brake and three non symmetrical positioned vent holes to counteract muzzle rise and climb as well as lateral shift to the right much like the AKM's offset muzzle brake. A flat plate near the end of the brake produces a forward thrust when emerging exhaust gases strike its surface, greatly reducing recoil. The muzzle brake prevents backblast from reaching the firer , although it is reported to be harsh on bystanders as the muzzle gases are dispersed to the sides. The standard-issue AK-74 muzzle brake has been subtly revised several times since the 1970s. Sights. Iron sights. The AK-74 uses an adjustable notched rear tangent iron sight calibrated in increments from . The front sight is a post adjustable for elevation in the field. Horizontal adjustment requires a special drift tool and is done by the armoury before issue or if the need arises by an armourer after issue. The sight line elements are approximately over the bore axis. The "point-blank  range" battle zero setting "П" standing for "постоянная" (constant/consistent/permanent) the 5.45×39mm AK-74 rear tangent sight element corresponds to a zero, compared with the zero for 7.62×39mm AKs. For the AK-74 combined with the 7N6 or 7N10 service cartridges the 400 m battle zero setting point-blank range limits the apparent "bullet rise" within approximately under the line of sight. At the corresponding maximum point-blank range the bullet will have dropped to approximately relative to the line of sight. Soldiers are instructed to fire at any target within this range by simply placing the sights on  the center of mass (the belt buckle, according to Russian and former Soviet doctrine) of the enemy target. Any errors in range estimation are tactically irrelevant, as a well-aimed shot will hit the torso of the enemy soldier. Optical sights. While most Russian and CIS armed forces use the AK-74 in its basic configuration with iron sights, many magnified and non-magnified optical sights are available for designated marksmen and other special purpose troops in their respective militaries. For the 5.45×39mm AK-74, the East German Zeiss ZFK 4×25, 1P29, Belorussian BelOMO PO 3.5×21P, PO 4×24P and the 1P78  Kashtan dedicated side rail mounted optical sights were developed. These optical sights are primarily designed for rapid target acquisition and first round hits out to 400 m, but by various means these optical sights also offer bullet drop compensation (BDC) (sometimes referred to as ballistic elevation) for aiming at more distant targets. The BDC feature compensates for the effect of gravity on the bullet at given distances (referred to as "bullet drop") in flat fire scenarios. The feature must be tuned for the particular ballistic trajectory of a particular combination of gun and cartridge at a predefined muzzle velocity and  air density. Since the usage of standardized ammunition is an important prerequisite to match the BDC feature to the external ballistic behaviour of the employed projectiles, these military optical sights are intended to assist with field shooting at varying medium to longer ranges rather than precise long range shots. The standard Russian side rail mounted optical sight was the 4×26 1P29 Universal sight for small arms. It was copied from and hence similar to the British SUIT (Sight Unit Infantry, Trilux). When mounted the 1P29 sight is positioned centered above the receiver at a height that allows the use of  the iron sights. It weighs 0.8 kg, offers 4× magnification with a field of view of 8° and 35 mm eye relief. The 1P29 is issued with a canvas pouch, a lens cleaning cloth, combination tool, two rubber eyecups, two eyecup clamps and three different bullet drop compensation (BDC) cams for the AK-74/AN-94, RPK-74 and PK machine gun. The 1P29 is intended for quickly engaging point and area targets at various ranges and is zeroed for both windage and elevation at . On the right side of the field of view a stadiametric rangefinder is incorporated that can be  used to determine the distance from a tall object from . The reticle is an inverted aiming post in the top half of the field of view and is tritium-illuminated for low-light condition aiming. The current Russian standard side rail mounted optical sight for the AK-74M is the 2.8×17 1P78 Kashtan, an aiming optic more similar to the American ACOG. When mounted the 1P78 sight is positioned centered above the receiver. It weighs 0.5 kg, offers 2.8× magnification with a field of view of 13° and 32 mm eye relief. The 1P78 comes in several versions for  the AK-74 (1P78-1), RPK-74 (1P78-2), AKM (1P78) and RPK (1P78-3). The 1P78 is intended for quickly engaging point and area targets at various ranges and is zeroed for both windage and elevation at . A stadiametric rangefinder is incorporated that can be used to determine the distance for a soldier sized target from . The reticle consist of a main 400 m "chevron" (^), a holdover dot and smaller additional holdover chevrons for and and is tritium-illuminated for low-light condition aiming. New features. The AK-74 was equipped with a new buttstock, handguard (which retained the AKM-type  finger swells) and gas cylinder. The stock has a shoulder pad different from that on the AKM, which is rubber and serrated for improved seating against the shooter. In addition, there are lightening cuts on each side of the buttstock. The buttstock, lower handguard and upper heatguard were first manufactured from laminated wood, this later changed to a synthetic, plum or dark brown colored fiberglass. The AK-74 gas tube has a spring washer attached to its rear end designed to retain the gas tube more securely. The lower handguard is fitted with a leaf spring that reduces play in the  rifle's lateral axis by keeping the wood tensioned between the receiver and the handguard retainer. The receiver remains nearly identical to that of the AKM; it is a U-shaped thick sheet steel pressing supported extensively by pins and rivets. The internal guide rails on which the bolt carrier travels are stamped and spot welded to the inside of the receiver housing. Minor changes were made to the front barrel and rear stock trunnions as well as the magazine well. All external metal surfaces are coated with a glossy black enamel paint. Accessories. Accessories supplied with the military version  of the rifle include a 6H4 or 6H5 type bayonet, a quick-loading device, three spare magazines, four 15-round stripper clips, maintenance kit, cleaning rod and sling. The bayonet is installed by slipping the muzzle ring around the flash hider and latching the handle down on the bayonet lug under the front sight base. The 6H5 AK-74 bayonet introduced in 1983 represents a further refinement of the 6H4 AKM bayonet. It introduced a radical blade cross-section, that has a flat milled on one side near the edge and a corresponding flat milled on the opposite side near the  false edge. The blade has a new spear point and an improved one-piece molded plastic grip making it a more effective fighting knife. It also has saw-teeth on the false edge and the usual hole for use as a wire-cutter. 5.45×39mm cartridge. Relatively small sized, light weight, high velocity military service cartridges like the 5.45×39mm allow a soldier to carry more ammunition for the same weight compared with their larger and heavier predecessor cartridges, have favourable maximum point-blank range or "battle zero" characteristics and produce relatively low bolt thrust and free recoil impulse, favouring  light weight arms design and automatic fire accuracy. Tests measured the free recoil energy delivered by the 5.45×39mm AK-74 rifle at , compared with delivered by the 7.62×39mm in the AKM. Early 5.45×39mm ballistics tests demonstrated a pronounced tumbling effect with high speed cameras. Some Western authorities believed this bullet was designed to tumble in flesh to increase wounding potential. At the time, it was believed that yawing and cavitation of projectiles were primarily responsible for tissue damage. Martin Fackler conducted a study with an AK-74 assault rifle using live pigs and ballistic gelatin; "The result of our  preset test indicate that the AK-74 bullet acts in the manner expected of a full-metal-cased military ammunition – it does not deform or fragment when striking soft tissues". Most organs and tissue were too flexible to be severely damaged by the temporary cavity effect caused by yaw and cavitation of a projectile. With the 5.45 mm bullet, tumbling produced a temporary cavity twice, at depths of and . This is similar to (but more rapid than) modern 7.62×39mm ammunition and to (non-fragmenting) 5.56×45mm NATO ammunition. Magazines. The original steel-reinforced 30-round AK-74 detachable box magazine was  similar to that of the AKM, except for minor dimensional changes required by the 5.45×39mm cartridge. These rust-colored magazines are often mistakenly identified as being made of Bakelite (a phenolic resin), but were actually fabricated from two-parts of AG-S4 molding compound (a glass-reinforced phenol-formaldehyde binder impregnated composite), assembled using an epoxy resin adhesive. Noted for their durability, these magazines did however compromise the rifle's camouflage and lacked the small horizontal reinforcing ribs running down both sides of the magazine body near the front that were added on all later AK-74 magazine generations. A  second generation steel-reinforced dark-brown (color shades vary from maroon to plum to near black) 30-round magazine was introduced in the early 1980s, fabricated from ABS plastic. The third generation steel-reinforced 30-round AK-74 magazine is similar to the second generation, but is darker colored and has a matte nonreflective surface finish. With the introduction of the AK-74M the fourth generation of steel-reinforced matte true black nonreflective surface finished 30-round AK-74 magazines was introduced. All AK-74 magazines have a raised horizontal rib on each side of the rear lug to prevent their use in  a 7.62×39mm AK. The magazines can be quickly recharged from stripper clips. The empty weight of a 30-round AK-74 box magazine is . The 45-round plastic box magazine of the RPK-74 light machine gun is also interchangeable with that of the AK-74. The empty weight of a 45-round RPK-74 box magazine is . Further 60-round and later 50-round quad-stack 5.45×39mm casket magazines were developed. The transition to mainly plastic magazines and the relatively small sized, light weight, high velocity 5.45×39mm cartridge yielded a significant weight reduction and allow a soldier to carry considerably  more rounds for the same weight compared with the previous Soviet AK-47 and AKM and later 7.62×39mm chambered AK platform assault rifles. Variants. The AK-74 series is also available in several "night-fighting" configurations, equipped with a side dovetail rail for mounting optical sights. These variants, the AK-74N, AKS-74N and AKS-74UN can be used in conjunction with NSPU and NSPU-3 (1PN51) night sights, as well as optical sights such as the USP-1 (1P29). The variants designated AK-74N2 and AKS-74N2 can use the multi-model night vision sight NSPUM (1PN58). AKS-74. The AKS-74 ("S"—Russian: ; "Skladnoy", or "folding"), is a variant  of the AK-74 equipped with a side-folding metal shoulder stock, designed primarily for use with air assault infantry and developed alongside the basic AK-74. Unlike the AKMS's somewhat fragile underfolding stock (modeled after the MP 40 submachine gun stock), the AKS-74 stock is fabricated from stamped sheet metal struts, machine pressed into a "U" shape and assembled by punch fit and welding. The stock has a triangular shape; it lacks the folding shoulder pad found on the AKMS stock and is folded to the left side of the receiver. The hinged stock is securely locked in its extended  position by a spring-loaded button catch located at the rear of the receiver. When folded, the stock is held closed by a spring-loaded capture hook situated on the left side at the front of the receiver housing. A rear-mounted sling swivel is also provided on the right side at the beginning of the stock frame. It retains the pistol grip reinforcement plate the AKMS used, though due to the less complex rear trunnion, only has one riveting hole in place of the three on the AKMS. AK-74M. In 1991 the Izhmash factory in the city of Izhevsk  began full-scale production of a modernised variant of the AK-74—the AK-74M ("М"—) assault rifle that offers more versatility compared with its predecessor. Apart from several minor improvements, such as a lightened bolt and carrier assembly to reduce the impulse of the gas piston and bolt carrier during firing, the rifle features a new glass-filled polyamide stock that retains the shape of the original AK-74 fixed laminated wood stock, but side-folds to the left like the skeletonised AKS-74 buttstock. As a result, pistol grip reinforcement plates that were once exclusively used on the folding stock variants  are standard on all AK-74Ms. Additionally the AK-74M features an improved muzzle device with extended collar and threads to reduce play and a machine cut beneath to allow easier cleaning rod removal, a reinforced smooth dust cover and a redesigned guide rod return spring retainer that allows firing the GP-25, GP-30 and GP-34 underslung grenade launchers without having to use the previously necessary additional receiver cover fastener. To reduce production costs, barrel hardware, such as the front sight base and gas block, are dimple pressed on to the barrel instead of pinned on (commercial semi-auto variants are still  pinned on to maintain user serviceability). Other economic changes include omission of lightening cuts on the front sight block and gas piston as well as a stamped gas tube release lever, replacing the milled one. The bullet guide and bolt guide were also separated, with the bolt guide becoming a simple bump held in place on the left side of the receiver with an additional rivet (often called a "bump rivet" because of this) making it easier to replace in case of wear. Each AK-74M is fitted with a side-rail bracket for mounting optics that is a simplified  version of the 74N mount with less machining cuts. The AK-74M would have been adopted by the Soviet Union as the standard service rifle, and has been accepted as the new service rifle of the Russian Federation. AK-74MR UUK (Universal Upgrade Kit). An AK-74M universal upgrade kit consisting of a new safety, dust cover and furniture featuring improved ergonomics and rails to attach accessories like aiming optics, optoelectronic sights, laser sights, weapon lights and vertical fore grips and a new muzzle device had its official debut on 9 May 2015 in Moscow as part of the 2015 Moscow  Victory Day Parade. The Kalashnikov Concern has further developed three sets of additional equipment for the modernization of 5.45×39mm and 7.62×39mm chambered AK-pattern assault rifles for normal military units, reconnaissance units, and special forces units. The Kalashnikov Concern announced it has a contract with the Russian Ministry of Defence to deliver upgrade kits for their AK-74M assault rifles. AKS-74U. In 1973, a design competition (codenamed "Modern"—Модерн) was started for the adoption of a fully automatic carbine. Soviet planners drew from the unsolicited design AO-46 built in 1969 by Peter Andreevich Tkachev, which weighed only 1.9 kg . The TTT specifications required a weight no greater than , a length of / with the stock unfolded/folded, and an effective firing range of . The competition was joined by designs of M.T. Kalashnikov (PP1), I.Y. Stechkin (TKB-0116), S.G. Simonov (AG-043), A.S. Konstantinov (AEK-958), and Yevgeny Dragunov (who called his model "MA"). Kalashnikov also presented an additional design (A1-75) which differed from PP1 by having a modified muzzle for flash and noise suppression. In 1977, the GRAU decided to adopt Kalashnikov's model, which was largely a shortened AKS-74, because its performance was no worse than the competition, and promised significant  production cost savings by utilizing existing equipment for the AK-74 line. A final round of large scale testing with Kalashnikov's model was performed by airborne divisions in the Transcaucasian Military District in March 1977. The AKS-74U ("U"—Russian: ; "Ukorochenniy", or "shortened") was officially adopted in 1979, and given the official, but seldom used GRAU designation 6P26. In 1993 production stopped. The AKS-74U bridges the tactical deployment gap between a submachine gun and an assault rifle. It was intended for use mainly with special forces, airborne infantry, rear-echelon support units, helicopter and armored vehicle crews. It has been augmented and  replaced by various submachine guns, and the less compact AK-105 carbine in Russian military service. It is commonly used by law enforcement; for example, each urban police foot patrol is issued at least one. The rifle's compact dimensions, compared with the AKS-74, were achieved by using a short barrel (this forced designers to simultaneously reduce the gas piston operating rod to an appropriate length). Due to the shortening of the operating mechanism the cyclic rate of fire rose slightly to around 700-735 rounds per minute. In order to effectively stabilize projectiles, the barrel's twist rate was increased  from 200 mm (1:7.87 in) or 37 calibers rifling twist rate to 160 mm (1:6.3 in) or 29.6 calibers rifling twist rate to adapt the AKS-74U for muzzle velocities of and higher. A new gas block was installed at the muzzle end of the barrel with a muzzle booster, which features an internal expansion chamber inside the cylindrical section of the booster while the conical end acts as a nozzle to increase net pressure inside the gas chamber by supplying an increased amount of propellant gases from the barrel. The chrome-lined muzzle booster also burns any remaining propellant, which  would normally reduce muzzle blast. However, due to the extremely short barrel and conical end of the booster, the muzzle blast is nevertheless extremely large and visible. The muzzle device locks into the gas block with a spring-loaded detent pin and features two parallel notches cut into the edge of the flash hider cone, used for unscrewing it using the cleaning rod. Unlike most Kalashnikov variants there is no provision to store the cleaning rod under the barrel. The front sight was integrated into the gas block/forward sling loop. The sight height above the bore axis is also  approximately higher than the AK-74, due to the combined front sight/gas block, rear sight configuration. The AKS-74U has a different rear sight composed of a U-shaped flip sight on the top cover instead of the standard sliding notch tangent rear sight. This rear sight has two settings: "П" standing for "постоянная" (constant) corresponding to a "point-blank range" battle zero setting and "4-5" (used for firing at distances between ). The rear sight is housed in a semi-shrouded protective enclosure that is riveted to the receiver's spring-loaded top cover. This top cover hinges from a  barrel trunnion (hinging where the rear sight on a normal AK74 is located), pivoting forward when opened, which also works to unlock the gas tube cover. Both the gas tube and handguard are also of a new type and are wider and shorter than the analogous parts in the AKS-74. For the AKS-74s combined with the 7N6 or 7N10 service cartridges the 350 m battle zero setting limits the apparent "bullet rise" within approximately relative to the line of sight. Soldiers are instructed to fire at any target within this range by simply placing the sights on the center of  mass (the belt buckle) of the enemy target. Any errors in range estimation are tactically irrelevant, as a well-aimed shot will hit the torso of the enemy soldier. The AKS-74U is significantly more maneuverable in tight quarters than the AKS-74; however, the significant decline in muzzle velocity to resulted in a reduction in effective range to (the effective hitting distance for a "running"-type silhouette target was reduced from to ). The AKS-74U cannot mount a bayonet or standard under-barrel grenade launcher. However, a suppressed 30 mm BS-1 grenade launcher was developed specifically for that platform that fires a  high-explosive dual purpose (HEDP) grenade. The grenades for the BS-1 are launched by special blank cartridges that are inserted into the grenade launcher via a detachable magazine. The majority of AKS-74U carbines were manufactured at the Tula Arms Factory rather than Izhmash. There were some accessories produced for the AKS-74U including a plastic thigh holster and (shorter than standard) 20-round AK-74 type magazines. The rifle utilizes a proprietary 25 mm wide sling that differs from the standard 35 mm AK sling also in construction. The AKS-74U also exists in a version featuring modernized synthetic furniture made from a  black, glass-filled polyamide. The AKS-74U was also used as the basis for several other unique weapons, including the bullpup OTs-14 Groza specialist carbine which is now in limited service in the Russian military, and the Gepard series of multi-caliber submachine guns (none of which evolved past prototype stage). In the United States, the AKS-74U is called a "Krinkov". The origin of this term is uncertain. A hypothesis was circulating that the name came from the Mujahideen who supposedly had captured a high-ranking Soviet officer armed with an AKS-74U, and that they had named it after him. However , investigation by Patrick Sweeney could not confirm this hypothesis, for no Soviet officer with a resembling name was captured in Afghanistan. US journalist C. J. Chivers reported that the gun was nicknamed "the Osama" in jihadist circles, after Osama bin Laden was photographed next to an AKS-74U. Research by The Firearm Blog published in 2016 suggests that the name "Krinkov" is a Pashtun invention that came to the United States with accounts of the Mujahideen. The AKS-74U is approximately lighter than the NATO equivalent XM177, and shorter with the stock folded. Due to the fact that the AKS-74U is moderately  concealable with its stock folded and capable of easily defeating IIIa soft body armour, it continues to be able to perform the role of a modern Personal Defense Weapon, despite being designed in the 1970s. AKS-74UB. The AKS-74UB ("B"—Russian: ; "Besshumniy" or "silent") is a sound-suppressed variant of the AKS-74U adapted for use with the PBS-4 suppressor (used in combination with subsonic 5.45×39mm Russian ammunition). Post AK-74M developments and successors. AK-100 series. The modernised variant of the AK-74 — the AK-74M — was used as the technical basis for the new Russian AK-100 family of Kalashnikov firearms: These original  AK-100 series firearms were introduced in 1994 and are categorized by all having black polymer handguards, folding polymer stocks, and use of AK-74M internal systems. Parts are highly interchangeable. The AK-101, AK-102, AK-103 and AK-104 are destined primarily for export, while the AK-105 was developed for replacing the shorter barreled AKS-74U. The AK-105 is used by the Russian Army and Ministry of Internal Affairs. Additionally, the 5.45×39mm AK-107, 5.56×45mm NATO AK-108 and 7.62×39mm AK-109 assault rifles were developed. These have a technically differing balanced recoil system to reduce felt recoil and muzzle rise. This balanced recoil  system designed by Yuriy K. Alexandrov for Kalashnikov-pattern rifles is a significant change to the Kalashnikov operating system of the 1940s. The operating system of these new rifles was derived from the AL-7 experimental rifle of the early 1970s. Since their development, these rifles met little commercial success. AK-12. In 2010, the AK-12 series of proposed prototype models were unveiled. They differed in weight, introduced a new recoil compensation technology and improved ergonomics. The rear iron sight element was rail-mounted and moved to the back of the upper receiver to lengthen the sight line, and the full length  of the weapon featured a Picatinny rail for mounting accessories such as aiming optics on top. The hand guard features Picatinny rails on both sides and its underside for mounting accessories like tactical lights, laser sights and grenade launchers. Throughout its development and evaluation stage the multiple modifications were applied to meet Russian military standards, as well as to improve upon the "range of defects" that were discovered on prototype models and to addresses concerns regarding the cost of earlier prototypes. In September 2016 the prototype models were replaced by the final production models of the AK-12 (chambered in 5.45×39 mm) and AK-15 (chambered in 7.62×39mm) assault rifles. Parallel developments are the RPK-16 light machine gun and the AM-17 compact assault rifle (both chambered in 5.45×39mm). The AK-12, AK-15 and RPK-16 technically stronger resemble the AK-74M, AK-100 series and RPK-74M than the earlier prototypes and the arms manufacturer Kalashnikov concern hopes they will replace these Russian service guns. In late 2016 it was reported the AK-12 production model was undergoing troop trials with the Russian Army, where it competes against the Degtyarov A-545 balanced action assault rifle in Ratnik program trials. The AK-12 completed its operational  testing and passed military field tests in June 2017, paving the way to Russian Army adoption, potentially under the Ratnik program. Both AK-12 and AK-15 completed testing in December 2017. In January 2018 it was announced that the AK-12 and AK-15 have been adopted by the Russian military. Accuracy potential. The following table represents the Russian method for determining accuracy and it is far more complex than Western methods. In the West, one fires a group of shots into the target and then simply measure the overall diameter of the group. The Russians on the other hand, fire a group  of shots into the target. They then draw two circles on the target: one for the maximum vertical dispersion of hits and one for the maximum horizontal dispersion of hits. They then disregard the hits on the outer part of the target and only count half of the hits (50% or R) on the inner part of the circles. This dramatically reduces the overall diameter of the groups. They then use both the vertical and horizontal measurements of the reduced groups to measure accuracy. This circular error probable method used by the Russian and other European militaries cannot be  converted and is not comparable to US military methods for determining rifle accuracy. When the R results are doubled the hit probability increases to 93.7%. In general, this is more accurate than the AK-47 and the AKM. The vertical and horizontal mean (R) deviations with service ammunition at for four Russian rifles are: The single-shot hit-probability on the NATO E-type Silhouette Target (a human upper body half and head silhouette) of the AK-47, AK-74 and M16A1 and M16A2 assault rifles were measured by the US military under ideal proving ground conditions in the 1980s as follows: Under  worst field exercise circumstances, due to range estimation and aiming errors, the hit probabilities for the tested assault rifles were drastically reduced with differences without operational significance.