AK-47

The AK-47 is a selective-fire, gas-operated 7.62×39mm assault rifle, first developed in the USSR by Mikhail Kalashnikov. It is officially known as Avtomat Kalashnikova (Russian: Автомат Калашникова). It is also known as a Kalashnikov, an AK or in Russian slang, Kalash.
Design work on the AK-47 began in the last year of World War II (1945). After the war in 1946, the AK-46 was presented for official military trials. In 1947 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 and used by the majority of the member states of the Warsaw Pact.
The original AK-47 was one of the first true "assault rifles" to be manufactured, after the original Sturmgewehr 44.Even after six decades the model and its variants remain the most widely used and popular assault rifles in the world because of their durability, low production cost, and ease of use. It has been manufactured in many countries and has seen service with armed forces as well as irregular forces worldwide. The AK-47 was the basis for developing many other types of individual and crew-served firearms. More AK-type rifles have been produced than all other assault rifles combined

Design

The first assault rifle to see service was created in 1915 by Vladimir Fyodorov, following the experience gathered in the Russo-Japanese War. Several countries had already developed and adopted low-power rifle cartridges since 1890s (such as 6.5×52mm Mannlicher-Carcano) as their standard infantry ammunition. The Russo-Japanese war, however, had demonstrated the regular rifles' lack of suppressive firepower, in addition to the excessive range of their ammunition. The latter was also confirmed in World War I. The Fyodorov's assault rifle went out of production after the Soviet armed forces decided to standardize its infantry weaponry around only the most popular types of cartridges following the Russian Civil War. The Soviet Union had returned to the development of an assault rifle in 1942 when the need for an intermediate-powered rifle became clearly evident.By that time submachine guns were already in widespread use but they could not replace service rifles because of limited power of pistol cartridges. Like the Germans, the Soviets designed an intermediate cartridge that could be made on existing production lines (despite Vladimir Fyodorov's insistence on a special small-calibre cartridge) he work on the weapons for the new ammunition commenced in 1943, with the AK-47 of Mikhail Kalashnikov, the SKS-45 of Sergei Simonov and the RPD of Vasily Degtyaryov emerging as the victors.
Mikhail Kalashnikov began his career as a weapon designer while in a hospital after he was shot in the shoulder during the Battle of Bryansk. After tinkering with a submachine gun design, he entered a competition for a new weapon that would chamber the 7.62×41mm cartridge developed by Yelizarov and Syomin in 1943 (the 7.62×41mm cartridge predated the current 7.62×39mm M1943). A particular requirement of the competition was the reliability of the firearm in the muddy, wet, and frozen conditions of the Soviet front line. Kalashnikov designed a carbine, strongly influenced by the American M1 Garand, that lost out to the Simonov design (scaled down PTRS-41), that later became the SKS semi-automatic carbine. At the same time, the Soviet Army was interested in developing a true assault rifle employing a shortened M1943 round. The first such weapon was presented by Sudayev in 1944, but trials found it to be too heavy. A new design competition was held two years later where Kalashnikov and his design team submitted an entry. It was a gas-operated rifle which had a breech-block mechanism similar to his 1944 carbine, and a curved 30-round magazine.

Kalashnikov's rifles (codenamed AK-1 and −2) proved to be reliable and the weapon was accepted to second round of competition along with designs by A. A. Dementyev and A. A. Bulkin. In late 1946, as the rifles were being tested, one of Kalashnikov's assistants, Aleksandr Zaitsev, suggested a major redesign of AK-1, particularly 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. The new rifle was produced for a second round of firing tests and field trials. There, Kalashnikov assault rifle model 1947 proved to be simple and reliable under a wide range of conditions with convenient handling characteristics. Production began on 6 July 1947, and in 1949 it was adopted by the Soviet Army as "7.62mm Kalashnikov assault rifle (AK)".
The AK-47 is best described as a hybrid of previous rifle technology innovations: the trigger, double locking lugs and unlocking raceway of the M1 Garand/M1 carbine, the safety mechanism of the John Browning designed Remington Model 8 rifle,and the gas system of the Sturmgewehr 44. Kalashnikov's team had access to all of these weapons and had no need to "reinvent the wheel"though he denied that his design was based on the German Sturmgewehr 44 assault rifle.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." There are claims about Kalashnikov copying other designs, like Bulkin's TKB-41 or Simonov's AVS-31

Features

The main advantages of the Kalashnikov rifle are its simple design, fairly compact size, and adaptation to mass production. It is inexpensive to manufacture and easy to clean and maintain. Its ruggedness and reliability are legendary. The AK-47 was initially designed for ease of operation and repair by glove-wearing Soviet soldiers in Arctic conditions. 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. This reliability comes at the cost of accuracy, as the looser tolerances do not allow for precision and consistency[citation needed]. Reflecting Soviet infantry doctrine of its time, the rifle is meant to be part of massed infantry fire, not long range engagements.
Aside from USSR the AK-47 and its variants were/are made in dozens of countries, with “quality ranging from finely engineered weapons to pieces of questionable workmanship.”For example, Arsenal-made AK has a system life of 15,000 rounds
The bore and chamber,as well as the gas piston and the interior of the gas cylinder, are generally chromium-plated. This plating dramatically increases the life of these parts by resisting corrosion and wear. This is particularly important, as most military-production ammunition (and virtually all ammunition produced by the Soviet Union and other Warsaw Pact nations) during the 20th century contained potassium chlorate in the primers. On firing, this was converted to corrosive and hygroscopic potassium chloride which mandated frequent and thorough cleaning in order to prevent damage. Chrome plating of critical parts is now common on many modern military weapons

Varient

Early variants (7.62×39mm)
AK-47 1948–51 – The very earliest models, with the Type 1 stamped sheet metal receiver, are now very rare.
AK-47 1952 – Has a milled receiver. Barrel and chamber are chrome plated to resist corrosion. Rifle weight is 4.2 kg (9.3 lb).
AKS – Featured a downward-folding metal stock similar to that of the German MP40, for use in the restricted space in the BMP infantry combat vehicle, as well as by paratroops.
AKN (AKSN) – Night scope rail.

Modernized (7.62×39mm)
AKM – A simplified, lighter version of the AK-47; Type 4 receiver is made from stamped and riveted sheet metal (see schematic above). A slanted muzzle device was added to counter climb in automatic fire. Rifle weight is 3.1 kg (6.8 lb) due to the lighter receiver. This is the most ubiquitous variant of the AK-47.
AKMS – Under-folding stock version of the AKM intended for airborne troops.
AKMN (AKMSN) – Night scope rail.
AKML (AKMSL) – Slotted flash suppressor and night scope rail.
RPK – Hand-held machine gun version with longer barrel and bipod
RPKS – Side-folding stock.
RPKN (RPKSN) – Night scope rail.
RPKL (RPKSL) – Slotted flash suppressor and night scope rail.

Low-impulse variants (5.45×39mm)
AK-74 – Assault rifle.
AKS-74 – Side-folding stock.
AK-74N (AKS-74N) – Night scope rail.
AKS-74U – Compact carbine.
AKS-74UN – Night scope rail.
RPK-74 – Light machine gun.
RPKS-74 – Side-folding stock.
RPK-74N (RPKS-74N) – Night scope rail.

The 100 Series

5.45×39mm / 5.56×45mm / 7.62×39mm
AK-74M/AK-101/AK-103 – Modernized AK-74. Scope rail and side-folding stock.
AK-107/AK-108 – Balanced recoil models.
AK-105/AK-102/AK-104 – Carbine.
PRK-74M / RPK-201 / RPKM and RPK-203 – Light machine gun.