AK-47

The **AK-47** (also known as the **Kalashnikov**, **AK**, or in Russian slang, **Kalash**) is a selective-fire (semi-automatic and automatic), gas-operated 7.62×39mm assault rifle, developed in the Soviet Union by Mikhail Kalashnikov. It is officially known in the Soviet documentation as *Avtomat Kalashnikova* (Russian: Автомат Калашникова).

Design work on the AK-47 began in the last year of World War II
(1945). In 1946, the AK-47 was presented for official military trials,
and in 1948, the fixed-stock version was introduced into active service
with selected units of the Soviet Army. An early development of the design was the *AKS* (S—*Skladnoy* or "folding"), which was equipped with an underfolding metal shoulder stock. In 1949, the AK-47 was officially accepted by the Soviet Armed Forces[7] and used by the majority of the member states of the Warsaw Pact.
Even after almost seven decades, the model and its variants remain
the most popular and widely used assault rifles in the world because of
their substantial reliability under harsh conditions, low production
costs compared to contemporary Western weapons, availability in
virtually every geographic region and ease of use. The AK-47 has been
manufactured in many countries and has seen service with armed forces as
 well as irregular forces
 worldwide, and was the basis for developing many other types of
individual and crew-served firearms. As of 2004..."Of the estimated 500
million firearms worldwide, approximately 100 million belong to the
Kalashnikov family, three-quarters of which are AK-47.

## History

### Origins

Throughout World War II, Soviet soldiers found themselves
consistently outgunned by heavily armed German troops, especially those
armed with the Sturmgewehr StG 44 assault rifles, which the Germans fielded in large numbers.[8][3][9][10][11][12][13][14] The select-fire StG 44 was chambered for a new intermediate cartridge, the 7.92×33mm Kurz, and combined the firepower of a submachine gun with the range and accuracy of a rifle.[9]

On 15 July 1943, a Sturmgewehr was demonstrated before the People's Commissariat of Arms of the USSR.[15]
 The Soviets were so impressed with the Sturmgewehr, that they
immediately set about developing an intermediate caliber automatic rifle
 of their own, to replace the badly outdated Mosin–Nagant bolt-action rifles and PPSh-41 submachine guns that armed most of the Soviet Army.[11][14][15][16][17][18]

The Soviets soon developed the 7.62×39mm M43 cartridge, the semi-automatic SKS carbine and the RPD light machine gun.[19]
 Shortly after World War II, the Soviets developed the AK-47 assault
rifle, which would quickly replace the SKS in Soviet service.[20][21] In the 1960s, the Soviets introduced the RPK
 light machine gun, itself an AK-47 type weapon with a stronger
receiver, a longer heavy barrel, and a bipod, that would eventually
replace the RPD light machine gun.[19]

### Concept

A Type 2 AK-47, the first machined receiver variation

Mikhail Kalashnikov began his career as a weapon designer in 1941, while recuperating from a shoulder wound, which he received during the Battle of Bryansk.[3][22]
 Kalashikov himself stated..."I was in the hospital, and a soldier in
the bed beside me asked: ‘Why do our soldiers have only one rifle for
two or three of our men, when the Germans have automatics?’ So I
designed one. I was a soldier, and I created a machine gun for a
soldier. It was called an Avtomat Kalashnikova, the automatic weapon of
Kalashnikov—AK—and it carried the date of its first manufacture, 1947." [23]

The AK-47 is best described as a hybrid of previous rifle technology
innovations. "Kalashnikov decided to design an automatic rifle combining
 the best features of the American M1 and the German StG44."[24]
 Kalashnikov's team had access to these weapons and had no need to
"reinvent the wheel". Kalashnikov himself observed: "A lot of Russian
Army soldiers ask me how one can become a constructor, and how new
weaponry is designed. These are very difficult questions. Each designer
seems to have his own paths, his own successes and failures. But one
thing is clear: before attempting to create something new, it is vital
to have a good appreciation of everything that already exists in this
field. I myself have had many experiences confirming this to be so."[22]

There are claims about Kalashnikov copying other designs, like Bulkin's TKB-415[25] or Simonov's AVS-31.[26]

### Early designs

Kalashnikov started tinkering with a submachine gun design in 1942[27] and with a light machine gun in 1943.[28][29]
 "Early in 1944, Kalashnikov was given some M1943 7.62×39mm cartridges
and informed that there were several designers working on weapons for
this new Soviet small-arms cartridge. It was suggested to him that this
new weapon might well lead to greater things, and he undertook work on
the new rifle."[30]
 In 1944, he entered a design competition with this new 7.62×39mm,
semi-automatic, gas-operated, long stroke piston, carbine, strongly
influenced by the American M1 Garand.[31] "The rifle that Kalashnikov designed was in the same class as the familiar SKS-45 Simonov with fixed magazine and gas tube above the barrel."[30] However, this new Kalashnikov design lost out to a Simonov design.[32]

In 1946, a new design competition was initiated to develop a new assault rifle.[33]
 Kalashnikov submitted an entry. It was gas-operated rifle with a
short-stroke gas piston above the barrel, a breech-block mechanism
similar to his 1944 carbine, and a curved 30-round magazine.[34] Kalashnikov's rifles AK-1 (with a milled receiver)
 and AK−2 (with a stamped receiver) proved to be reliable weapons and
were accepted to a second round of competition along with other designs.

These prototypes (also known as the AK-46) had a rotary bolt, a
two-part receiver with separate trigger unit housing, dual controls
(separate safety and fire selector switches) and a non-reciprocating
charging handle located on the left side of the weapon.[34][35]
 In late 1946, as the rifles were being tested, one of Kalashnikov's
assistants, Aleksandr Zaitsev, suggested a major redesign to improve
reliability. At first, Kalashnikov was reluctant, given that their rifle
 had already fared better than its competitors. Eventually, however,
Zaitsev managed to persuade Kalashnikov.

In November 1947, the new prototypes (AK-47s) were completed. It
utilized a long-stroke gas piston above the barrel. The upper and lower
receivers were combined into a single receiver. The selector and safety
were combined into a single control-lever/dust-cover on the right side
of the rifle. And, the bolt-handle was simply attached to the
bolt-carrier. This simplified the design and production of the rifle.
The first army trial series began in early 1948.[36]
 The new rifle proved to be reliable under a wide range of conditions
with convenient handling characteristics. In 1949, it was adopted by the
 Soviet Army as "7.62 mm Kalashnikov assault rifle (AK)".[7]

### Further development

AKMS with a stamped Type 4B receiver (top), and an AK-47 with a milled Type 2A receiver

1955 AK-47 with a milled Type 3A receiver showing the milled lightening
cut on the side above the magazine that for Type 3 receivers is slanted
to the barrel axis

There were many difficulties during the initial phase of production. The first production models had stamped sheet metal receivers
 with a milled trunnion and butt stock insert, and a stamped body.
Difficulties were encountered in welding the guide and ejector rails,
causing high rejection rates.[37] Instead of halting production, a heavy[N 2]
 machined receiver was substituted for the sheet metal receiver. This
was a more costly process, but the use of machined receivers accelerated
 production as tooling and labor for the earlier Mosin–Nagant rifle's machined receiver were easily adapted.[38]
 Partly because of these problems, the Soviets were not able to
distribute large numbers of the new rifle to soldiers until 1956. During
 this time, production of the interim SKS rifle continued.[37]

Once the manufacturing difficulties of non milled receivers had been overcome, a redesigned version designated the AKM (M for "modernized" or "upgraded"; in Russian: *Автомат Калашникова Модернизированный [Avtomat Kalashnikova Modernizirovanniy])* was introduced in 1959.[39] This new model used a stamped sheet metal receiver and featured a slanted muzzle brake on the end of the barrel to compensate for muzzle rise
 under recoil. In addition, a hammer retarder was added to prevent the
weapon from firing out of battery (without the bolt being fully closed),
 during rapid or automatic fire.[37]
 This is also sometimes referred to as a "cyclic rate reducer", or
simply "rate reducer", as it also has the effect of reducing the number
of rounds fired per minute during automatic fire. It was also roughly
one-third lighter than the previous model.[39]

stock. A large hole is present on each side to accommodate the hardware
for the underfolding stock.
 Type 2A/B
production in 1949. The Type 2A has a distinctive socketed metal "boot"
connecting the butt stock to the receiver and the milled lightening cut
 Type 3A/B
stock. It went into production between 1953 and 1954. The most
ubiquitous example of the milled-receiver AK-47. The milled lightening
 Type 4A/B
 supported extensively by pins and rivets. It went into production in
1959. Overall, the most-used design in the construction of the AK-series
 rifles.

Both licensed and unlicensed production of the Kalashnikov weapons
abroad were almost exclusively of the AKM variant, partially due to the
much easier production of the stamped receiver. This model is the most
commonly encountered, having been produced in much greater quantities.
All rifles based on the Kalashnikov design are frequently referred to as
 AK-47s in the West, although this is only correct when applied to
rifles based on the original three receiver types.[40]
 In most former Eastern Bloc countries, the weapon is known simply as
the "Kalashnikov" or "AK". The differences between the milled and
stamped receives including the use of rivets rather than welds on the
stamped receiver, as well as the placement of a small dimple above the
magazine well for stabilization of the magazine.

### Replacement

In 1974, the Soviets began replacing their AK-47 and AKM rifles with a newer design, the AK-74, which uses 5.45×39mm ammunition. This new rifle and cartridge had only started to be manufactured in Eastern European nations when the Soviet Union collapsed, drastically slowing production of the AK-74 and other weapons of the former Soviet bloc.

## Design

The AK-47 was designed to be a simple, reliable automatic rifle that
could be manufactured quickly and cheaply, using mass production methods
 that were state of the art in the Soviet Union during the late 1940s.[41] The AK-47 uses a long stroke gas system that is generally associated with great reliability in adverse conditions.[31][42][43]
 The large gas piston, generous clearances between moving parts, and
tapered cartridge case design allow the gun to endure large amounts of
foreign matter and fouling without failing to cycle.

### Cartridge

Main article: 7.62×39mm

Wound Profiles of Russian small-arms ammunition compiled by Dr. Martin Fackler on behalf of the U.S. military

The AK fires the 7.62×39mm cartridge with a muzzle velocity of 715 m/s (2,350 ft/s).[6] The cartridge weight is 16.3 g (0.6 oz), the projectile weight is 7.9 g (122 gr).[44] The original Soviet M43 bullets are 123 grain boat-tail bullets
 with a copper-plated steel jacket, a large steel core, and some lead
between the core and the jacket. The AK has excellent penetration when
shooting through heavy foliage, walls or a common vehicle's metal body
and into an opponent attempting to use these things as cover. The
7.62×39mm M43 projectile does not generally fragment when striking an
opponent and has an unusual tendency to remain intact even after making
contact with bone. The 7.62×39mm round produces significant wounding in
cases where the bullet tumbles (yaws) in tissue,[45] but produces relatively minor wounds in cases where the bullet exits before beginning to yaw.[46][47][48] In the absence of yaw, the M43 round can pencil through tissue with relatively little injury.[46][49]
Most, if not all, of the 7.62×39mm ammunition found today is of the
upgraded M67 variety. This variety deleted the steel insert, shifting
the center of gravity rearward, and allowing the projectile to
destabilize (or yaw) at about 3.3 in (8.4 cm), nearly 6.7 in (17 cm)
earlier in tissue than the M43 round.[50]
 This change also reduces penetration in ballistic gelatin to ~25 in
(64 cm) for the newer M67 round versus ~29 in (74 cm) for the older M43
round.[50][51]
 However, the wounding potential of M67 is mostly limited to the small
permanent wound channel the bullet itself makes, especially when the
bullet yaws.[50]

### Operating mechanism

The gas-operated mechanism of a Chinese AK-47

To fire, the operator inserts a loaded magazine, pulls back and releases the charging handle, and then pulls the trigger.
 In semi-automatic, the firearm fires only once, requiring the trigger
to be released and depressed again for the next shot. In full-automatic,
 the rifle continues to fire automatically cycling fresh rounds into the
 chamber, until the magazine is exhausted or pressure is released from
the trigger. 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
5.5 mm (0.2 in) 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. The AK-47 does not have a gas valve;
excess gases are ventilated through a series of radial ports in the gas
cylinder. The Kalashnikov operating system offers no primary extraction
upon bolt rotation, but uses an extractor claw to eject the spent
cartridge case.[52]

### Barrel

The rifle received a barrel with a chrome-lined
 bore and four right-hand grooves at a 240 mm (1 in 9.45 in) rifling
twist rate. The gas block contains a gas channel that is installed at a
slanted angle in relation to the bore axis. The muzzle is threaded for
the installation of various muzzle devices such as a muzzle brake or a blank-firing adaptor. The standard AK-47 barrel does not counteract muzzle rise and climb as well lateral shift to the right much like the AKM's offset muzzle brake.

### Fire selector

Vietcong guerrilla stands beneath a Vietcong flag carrying his AK-47

The fire selector is a large lever located on the right side of the
rifle, it acts as a dust-cover and prevents the charging handle from
being pulled fully to the rear when it is on safe.[53] It is operated by the shooter's right fore-fingers and has 3 settings: safe (up), full-auto (center), and semi-auto (down).[53]
 The reason for this is that under stress a soldier will push the
selector lever down with considerable force bypassing the full-auto
stage and setting the rifle to semi-auto.[53] To set the AK-47 to full-auto requires the deliberate action of centering the selector lever.[53]
 To operate the fire selector lever, right handed shooters have to
briefly remove their right hand from the pistol grip, which is
ergonomically sub-optimal. Some AK-type rifles also have a more
traditional selector lever on the left side of the receiver just above
the pistol grip.[53]
 This lever is operated by the shooter's right thumb and has three
settings: safe (forward), full-auto (center), and semi-auto (backward).[53]

### Sights

Rear sight of a Chinese Type 56, featuring 100 to 800 m (109 to 875 yd) settings and omission of a battle zero setting

The AK-47 uses a notched rear tangent iron sight calibrated in 100 m (109 yd) increments from 100 to 800 m (109 to 875 yd).[54]
 The front sight is a post adjustable for elevation in the field.
Horizontal adjustment requires a special drift tool and is done by the
armory before issue or if the need arises by an armorer after issue. The
 "point-blank range" battle zero setting "*П*" on the 7.62×39mm AK-47 rear tangent sight element corresponds to a 300 m (328 yd) zero.[54][55] These settings mirror the Mosin–Nagant and SKS rifles which the AK-47 replaced. For the AK-47 combined with service cartridges the 300 m battle zero setting limits the apparent "bullet rise"
 within approximately −5 to +31 cm (−2.0 to 12.2 in) 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. Some AK-type rifles have a front sight with a flip-up
luminous dot that is calibrated at 50 m (55 yd), for improved night
fighting.[54]

### Stock

The AK-47 was originally equipped with a buttstock, handguard and an
upper heat guard made from solid wood. With the introduction of the Type
 3 receiver the buttstock, lower handguard and upper heatguard were
manufactured from birch plywood laminates.[38]
 Such engineered woods are stronger and resist warping better than the
conventional one-piece patterns, do not require lengthy maturing, and
are cheaper. The wooden furniture was finished with the Russian amber
shellac finishing process.[*citation needed*]

### Magazines

"Bakelite" rust-colored steel-reinforced 30-round plastic box 7.62×39mm
AK magazines. Three magazines have an "arrow in triangle" Izhmash arsenal mark on the bottom right. The other magazine has a "star" Tula arsenal mark on the bottom right

The standard magazine capacity is 30 rounds. There are also 10, 20, and 40-round box magazines, as well as 75-round drum magazines.

The AK-47's standard 30-round magazines have a pronounced curve that
allows them to smoothly feed ammunition into the chamber. Their heavy
steel construction combined with "feed-lips" (the surfaces at the top of
 the magazine that control the angle at which the cartridge enters the
chamber) machined from a single steel billet makes them highly resistant
 to damage. These magazines are so strong that "Soldiers have been known
 to use their mags as hammers, and even bottle openers."[56][57] This contributes to the AK-47 magazine being more reliable, but makes it heavier than U.S. and NATO magazines.

The early slab-sided steel AK-47 30-round detachable box magazines weigh .43 kg (0.95 lb) empty.[43]
 The later steel AKM 30-round magazines had lighter sheet-metal bodies
with prominent reinforcing ribs weighing .33 kilograms (0.73 lb) empty.[43][58]
 To further reduce weight a light weight magazine with an aluminum body
weighing .19 kg (0.42 lb) empty was introduced for the AKM that proved
to be insubstantial and was quickly withdrawn from service. As a
replacement steel-reinforced 30-round plastic 7.62×39mm box magazines
were introduced. These rust-colored magazines weigh .24 kg (0.53 lb) empty and 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.[59][60][61]
 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 plastic magazine generations.[61] A second generation steel-reinforced dark-brown (color shades vary from maroon to plum to near black) 30-round 7.62×39mm magazine was introduced in the early 1980s, fabricated from ABS
 plastic. The third generation steel-reinforced 30-round 7.62×39mm
magazine is similar to the second generation, but is darker colored and
has a matte nonreflective surface finish. The current issue
steel-reinforced matte true black nonreflective surface finished
7.62×39mm 30-round magazines, fabricated from ABS plastic weigh .25 kg
(0.55 lb) empty.[6]
 Early steel AK-47 magazines are 9.75 in (248 mm) long, and the later
ribbed steel AKM and newer plastic 7.62×39mm magazines are about 1 in
(25 mm) shorter.[62][63]

The transition from steel to mainly plastic magazines yields a
significant weight reduction and allows a soldier to carry more
ammunition for the same weight.

430 g (0.95 lb)
916 g (2.019 lb)[43]
 AKM (1957)
330 g (0.73 lb)
819 g (1.806 lb)[43][58]
 AK-103 (1994)
250 g (0.55 lb)
739 g (1.629 lb)[43][58]
9.62 kg (21.2 lb)

All 7.62×39mm AK magazines are backwards compatible with older AK variants.

10.12 kg (22.3 lb) is the maximum amount of ammo that the average
soldier can comfortably carry. It also allows for best comparison of the
 three most common 7.62×39mm AK platform magazines.

Most Yugoslavian and some East German AK magazines were made with
cartridge followers that hold the bolt open when empty; however, most AK
 magazine followers allow the bolt to close when the magazine is empty.

### Accessories

AK-47 6H3 bayonet and scabbard

Accessories supplied with the rifle include a 387 mm (15.2 in) long 6H3 bayonet
 featuring a 200 mm (7.9 in) long spear point blade. The AK-47 bayonet
is installed by slipping the 17.7 mm (0.70 in) diameter muzzle ring
around the muzzle and latching the handle down on the bayonet lug under
the front sight base.[64]

AK-103 with GP-34 Grenade Launcher

All current model AKM rifles can mount under-barrel 40 mm grenade launchers such as the GP-25 and its variants, which can fire up to 20 rounds per minute and have an effective range of up to 400 metres.[65]
 The main grenade is the VOG-25 (VOG-25M) fragmentation grenade which
has a 6 m (9 m) (20 ft (30 ft)) lethality radius. The VOG-25P/VOG-25PM
("jumping") variant explodes 0.5–1 metre (1.6–3.3 ft) above the ground.[66]

The AK-47 can also mount a (rarely used) cup-type grenade launcher, the Kalashnikov grenade launcher that fires standard RGD-5 Soviet hand-grenades. The maximum effective range is approximately 150 meters.[67] This launcher can also be used to launch tear-gas and riot control grenades.

All current AKs (100 series) and some older models, have side rails
for mounting a variety of scopes and sighting devices, such as the PSO-1 Optical Sniper Sight.[68]
 The side rails allow for removal and remounting of optical accessories
without interfering with the zeroing of the optic. However, the 100
series side folding stocks cannot be folded with the optics mounted.

## Characteristics

### Accuracy

The AK-47's accuracy has always been considered to be "good enough" to hit an adult male torso out to about 300 m (328 yd),[69][70]
 though even experts firing from prone or bench rest positions at this
range were observed to have difficulty placing ten consecutive rounds on
 target.[71] Nor could the weapon's accuracy be significantly improved with later designs, where its accuracy remained relatively mediocre.[71] An AK can fire a 10-shot group of 5.9 in (15 cm) at 100 m (109 yd),[72] and 17.5 in (44 cm) at 300 m (328 yd)[71]
 The newer stamped-steel receiver AKM models, while more rugged and less
 prone to metal fatigue, are actually less accurate than the
forged/milled receivers of their predecessors: the milled AK-47s are
capable of shooting 3 to 5 in (8 to 13 cm) groups at 100 yd (91 m),
whereas the stamped AKMs are capable of shooting 4 to 6 in (10 to 15 cm)
 groups at 100 yd (91 m).[70]

The best shooters are able to hit a man-sized target at 800 m
(875 yd) within five shots (firing from prone or bench rest position) or
 ten shots (standing).[73]

The single-shot hit-probability on the NATO E-type Silhouette Target
(a human upper body half and head silhouette) of the AK-47 and the later
 developed AK-74, M16A1 and M16A2 assault rifles were measured by the US
 military under ideal proving ground conditions in the 1980s as follows:
NATO E-type Silhouette Target

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.

### Service life

The AK-47 and its variants are made in dozens of countries, with
"quality ranging from finely engineered weapons to pieces of
questionable workmanship."[75] As a result, the AK-47 has a service/system life of approximately 6,000,[76] to 10,000,[77] to 15,000[78] rounds.[11] The AK-47 was designed to be a cheap, simple, easy to manufacture assault rifle,[79] perfectly matching Soviet military doctrine that treats equipment and weapons as disposable items.[80]
 As units are often deployed without adequate logistical support and
dependent on "battlefield cannibalization" for resupply, it is actually
more cost-effective to replace rather than repair weapons.[80]

The AK-47 has small parts and springs that need to be replaced every
few thousand rounds. However, "Every time it is disassembled beyond the
field stripping stage, it will take some time for some parts to regain
their fit, some parts may tend to shake loose and fall out when firing
the weapon. Some parts of the AK-47 line are riveted together. Repairing
 these can be quite a hassle, since the end of the rivet has to be
ground off and a new one set after the part is replaced."[54]