What are the differences between AK-47, AKM, AK-56, AK-74 and AK-101?

The AK family of assault rifles are pretty widespread around the world, because of their lower cost of manufacturing, lower tooling costs, general reliability under rough conditions and the fact that the former Soviet Union were pretty much handing them out like candy for years. Clones of the original AK design have also been manufactured by other countries: China, Bulgaria, Romania, even companies in the good ol' USA. Unfortunately, the media keeps referring to just about any assault rifle in the AK family as the "AK-47". This post aims to point out some members of the AK family and some of their major differences.

The AK is a Russian abbreviation for Avtomat Kalashnikova. The name Kalashnikova comes from the fact that its inventor is Mikhail Kalashnikov. The original development for this rifle started in 1945 and a prototype (the AK-46) was submitted for evaluation in 1946, but it was only in 1947 that it was cleared for production for use by select Soviet forces. There have been several improvements to the original design over the years and there are now many models in the AK family. With that little bit of history said, let's now study some of the key features of some models.

AK-47: This is the original version that was approved for use by the Soviets. It fires a 7.62x39 mm. cartridge. It was originally approved for some Soviet forces in 1947, which is why the name has 47 after it. During 1948-1951, it went into general production to be used by other Soviet military units as well (the Type-1 model). In 1952, the Type-2 version was introduced, which had a chrome plated barrel and receiver to resist corrosion and wear. The Soviets had originally tried to make the receiver out of stamped sheet metal, but didn't have the technology then to produce the part reliably. After a large number of rejections of faulty receivers, the Soviets opted to use a receiver made of forged steel, which was milled into the final shape using various machining operations. This made the overall production rate slower.

AK-47 Type 2 variant. Click on image to enlarge. Public domain image.

AKM: This is a popular variant of the AK family. This was created as an improvement of the original AK-47 design. The letter M in the name "AKM" stands for Modernizirovanniy, which is the Russian word for "modernized." The AKM design was developed in the 1950s and finally was approved for full production in 1959. It fires the same 7.62x39 mm as the AK-47 for backward compatibility. However, the design was much revised and enhanced from the original AK-47 to allow it to be mass-produced. The Soviets acquired modern mass production technologies from captured German engineers (including Hugo Schmeisser, the designer of the StG-44) and used those on the AKM. Among some of its improvements:

• Replacement of the milled receiver with a receiver made out of stamped sheet steel. Machining is a lot slower process than using a press to stamp parts. Hence, use of stamped parts made it much faster to produce AKMs.
• Using rivets instead of welds on the receiver, in order to speed up production.
• Improvements to barrel, gas ports etc. to speed up manufacturing and enhance reliability
• Weight reduction of approximately 1 kg. (2.2 pounds)
• Retains the chrome lined barrel and chamber of the AK-47 Type-2 variant, but the barrel is pressed and pinned to the receiver, instead of the AK-47 which has a threaded barrel that is screwed into the receiver.
• The barrel is the first in the AK family to have a slant compensator to reduce rifle climb, when shooting in automatic mode.
• Gas relief ports are moved forward to the gas block, instead of the gas tube.
• Bolt carrier was lightened slightly. The wooden stocks were also hollowed out as well, in order to reduce more weight.
• Sights on an AKM are calibrated to go up to 1000 meters, whereas AK-47s are only calibrated to go up to 800 meters.
• Changes to the metal treatment applied. The AKM is parkerized instead of blued like the AK-47.
• Uses modified spring and trigger assembly for better safety. The AKM fires in automatic mode only when the bolt is fully locked. The new trigger assembly also reduces "trigger bounce" and has a hammer release delay device to delay the release of the hammer by a few microseconds in automatic firing mode. The hammer release delay mechanism is sometimes incorrectly called a "rate reducer" by some people, but it doesn't appreciably change the cyclic rate of fire. Instead it allows the bolt group to settle in the forwardmost position after returning into the battery.

AKM assault rifle. Click on image to enlarge. Public domain image.

Note the slanted barrel tip: that is the slant compensator, which is one of the improvements over the original AK-47 design

The AKM was used by the Soviets, most Warsaw Pact countries, several African countries and many Asian countries as well. Manufacturing licenses, as well as necessary technical data, were sold for very nominal rates (or gifted for free!) to Warsaw Pact countries, as well as other "friendly" countries like Egypt and Iraq, so that they could make their own AKMs. Because of this, it became very widespread around the world. Many variants of this design still exist in use around the world today. One popular variant of the AKM is the AKMS, which features a folding metal stock instead of the fixed wooden stock of the AKM.

AK-56: This is a Chinese made variant of the AK family. While it is officially called the "Type-56", it is often referred to as the AK-56. Predictably, the number 56 indicates that the production of the Chinese models started in 1956.  In the initial stages, the type-56 was a direct copy of the AK-47 type-1 model. However, in the 1960s, the Chinese incorporated some of the AKM improvements (e.g. stamped sheet metal receiver and slant compensator) and made some of their own modifications into their type-56 model, but did not change their version number for some reason. One visual difference between the AKM and the AK-56 is that the front sight of an AK-47 or an AKM is a partially open type, whereas the type-56 model has a fully hooded front sight. 

Chinese sailor carrying a type-56 assault rifle. Click on image to enlarge. Public domain image.

The type-56 is the most prolific version of the AK family, since it was exported by the Chinese to various communist movements, especially in third world countries of Asia, South America and Africa. Nearly one in five (i.e. 20%)  of  AK type rifles in the world today is a type-56. When US forces were in Vietnam, the type-56 was found in enemy hands far more often than AKM or AK-47s.

AK-74: This was the next rifle that was officially adopted by the Soviet military in 1974. It was based on the AKM design. However, this variant fires 5.45x39 mm. ammunition instead of 7.62x39 mm. ammunition that the older variants fire. Because of this new cartridge, the barrel, receiver, magazine, firing mechanism, gas cylinder, springs and sights are also altered to accommodate the new cartridge's dimensions and power. This rifle's magazine is made of a plastic, which makes it much more durable than the metal magazines of the AK-47 and AKM. The magazine shape is also subtly altered with two extra horizontal ribs, in order to make it impossible to insert it into an older AK model (since they don't use the same ammunition anyway). The pistol grip is made of a polymer plastic as well. Some early AK-74s have wooden hand guards and butt stock, but they use laminated wood instead of the plain wood that the earlier AK models use. Some later versions of the AK-74 use entirely polymer furniture (i.e. butt stock, pistol grip and hand guards) which is usually plum colored or black colored. The butt stock also has some cuts in it to reduce overall weight and also provide an easy way to distinguish it from an AKM.

AK-74 assault rifle. Click on image to enlarge. Public domain image.

Note the laminated wood stock with distinctive cuts on the side, laminated wood hand guards and the dark-brown plastic magazine.

There are also variants, such as the AKS-74, which feature folding metal stocks instead of wooden stocks, AKS-74U, which is a shorter carbine form of the AKS-74, AK-74M which features black plastic furniture completely (i.e. no wood parts) and has a mounting rail on the left to attach telescopic sight models etc. The firearm issued by the Russian military since the early 1990s is the AK-74M model, though earlier AK-74/AKS-74 still remain in service as well.

AK-74M assault rifle. Note the complete lack of wooden parts. Click on image to enlarge.

AK-101: This is a variant of the AK family that is meant for the export market outside Russia. That is why it is chambered to fire NATO standard 5.56x45 mm. ammunition, which is standard in many countries around the world. Naturally, many of the other parts (barrel, receiver, magazine etc.) are also modified to fit the cartridge. In short, the AK-101 is essentially an AK-74M design resized for the NATO cartridge.

AK-101 assault rifle. Click on image to enlarge. Public domain image.

Like the AK-74M, it also has a mounting rail on the side to allow attaching many optical devices that are common in Russia and Europe.

These are only a few of the models in the AK family of assault rifles. Unfortunately, many people in the media insist on calling all of them "AK-47s", in spite of the major differences between all the models. Surprisingly, true AK-47s are actually quite rare these days, especially the Type-1 variant. Most of what is referred to in the media as an "AK-47" is usually not the original AK-47 model, the weapon in question is usually a variant of AKM, a Type-56, an AK-74 etc. This became painfully apparent to the blog author when he attended a court case as a juror. The prosecutor kept referring to a firearm presented as evidence as "an AK-47 assault rifle". As the case progressed, it emerged that the firearm in question had a different firing mechanism as it was incapable of automatic fire (it could only fire in semi-automatic mode), had a laminated stock, used stamped parts and was made by an American manufacturer named Ewbank Manufacturing from Winslow, Arizona.