The AK-47, or AK as it is officially known (Russian: Автома́т Кала́шникова, tr. Avtomát Kaláshnikova, lit. Kalashnikov’s Automatic Rifle), also known as the Kalashnikov, is a gas-operated, 7.62×39mm assault rifle, developed in the Soviet Union by Mikhail Kalashnikov. It is the originating firearm of the Kalashnikov rifle (or “AK”) family.
Design work on the AK-47 began in 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 early 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.
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 and insurgencies worldwide, and was the basis for developing many other types of individual, crew-served and specialized 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-47s”
A deep study of weapon variants was done and the need for an intermediate cartridge was seen in Fedorov Avtomat. This weapon was stated by MK to be his main inspration for the AK47.
The Soviets soon developed the 7.62×39mm M43 cartridge, the semi-automatic SKS carbine and the RPD light machine gun. Shortly after World War II, the Soviets developed the AK-47 assault rifle, which would quickly replace the SKS in Soviet service. In the 1960s, the Soviets introduced the RPK light machine gun, 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.
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. Kalashnikov 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.”
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 Fedorov Avtomat.” 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.”
There are claims about Kalashnikov copying other designs, like Bulkin’s TKB-415 or Simonov’s AVS-31.
Kalashnikov started work on a submachine gun design in 1942 and with a light machine gun in 1943. “Early in 1944, Kalashnikov was given some 7.62×39mm M43 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.” 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. “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.” However, this new Kalashnikov design lost out to a Simonov design.
In 1946, a new design competition was initiated to develop a new assault rifle. 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. 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. This design had many similarities to the STG 44 and other gun designs of the era. 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.
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
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. 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)”.
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. Instead of halting production, a heavy 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. 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.
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. 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 fully automatic fire. 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 fully automatic fire. It was also roughly one-third lighter than the previous model.