The AK goes by many names. Regardless of what one calls it when an AK talks, folks usually listen. The AK47 is the most ubiquitous small arm of the 20th Century. The term "AK" functions as a general term describing all kinds of Kalashnikov-type rifles.
Who Invented the AK47?
Soviet WWII veteran and famous small arms designer Mikhail Kalashnikov created the Avtomat Kalashnikova (AK) in 1947. He took inspiration from the earlier German Stg44 and its intermediate cartridge, 7.92x33 (8mm Kurz). The AK47 fed from detachable 30 round box magazines and used the then-new 7.62x39 cartridge. The Soviet military fully adopted the AK47 in the early 1950s, and it later became adopted by most Eastern Bloc militaries.
How Does the AK47 Work?
All AKs function by way of a robust long-stroke gas operating system. Gas from the fired round is tapped from the barrel to move the gas piston and attached bolt carrier rearward. As the bolt carrier moves back, the bolt rotates to unlock, then extracts and ejects the case. After the bolt carrier's final rearward travel, the recoil spring pushes the bolt carrier forward to pick up a fresh round to restart the cycle.
How are AK47s Made?
The original AK47 featured a reinforced stamped sheet metal receiver, with the front and rear trunnions riveted into place. Initial prototypes were very promising; however, issues arose once the rifle went into mass production due to shortcomings in quality control. Kalashnikov tweaked the design, changing the receiver from a stamping to a milled forging. Eventually, he worked the bugs out of the original process, and the AK went back to a stamped receiver. The improved stamped receiver version, now known as the AKM, went into full service in the early 1960s.
Which is Better: A Milled or Stamped AK47?
Merits exist for both milled and stamped receiver AKs. Several nations and manufacturers still make milled receiver AKs. Due to the robustness of their design, plenty of original milled AKs are still around from the 1950s. Some users prefer milled receiver AKs due to their increased durability even at the expense of additional weight. Stamped receiver AKs are lighter and nearly as durable as their milled counterparts. Most users and militaries choose the stamped AKM because they are willing to accept a slightly less durable rifle with the benefits of decreased weight. Millions of old stamped AKMs exist in functional condition to this day.
Where Are AK47s Made?
Russia originally manufactured the AK47. Initially, the Soviet Union sold or gave AKs to allies and sympathetic groups. Eventually, many allies and nations under Soviet influence started to produce Kalashnikovs of their own. Some countries, such as East Germany, Poland, and Romania, produced near faithful copies of the AKM. Other nations like Yugoslavia and China made AK style rifles with subtle design differences. Many former Eastern Bloc nations still have AK production capabilities for both military and civilian customers. America imports AKs for the civilian market in a "sporting" configuration, then converts them back to the original setup. Alternatively, US companies build AKs with US-made receivers and barrels with decommissioned Eastern Bloc AK parts. AKs made in the US with domestically produced parts have become prevalent in recent years also.
What Caliber Does the AK47 Use?
In recent decades the AK has been adapted to fire numerous calibers; however, 7.62x39 remains the most popular. Most 7.62x39 rounds feature a 123-grain full metal jacket (FMJ) projectile housed in a steel cartridge case. The AK fires 7.62x39 at roughly 2,300 feet per second, which is relatively low muzzle velocity. Due to the low velocity and light bullet weight (compared to most centerfire .30 caliber rounds), 7.62x39's ballistic effectiveness maxes out at around 500 yards. On the other hand, 7.62x39 is ideal for close-range shooting as long as bullet over-penetration is not a concern. 7.62x39 defeats cover and barriers much more effectively than smaller, high-velocity rounds at close to medium range.
Why are AK47s so Reliable?
Mikhail Kalashnikov designed his rifle for ultimate reliability in all conditions. The bolt, carrier and gas piston are very robust with plenty of mass. AKs use an over-pressurized gas system that cycles the action briskly. The design includes a large amount of clearance around the various moving parts. Heavy fouling and environmental elements have much less of an effect on the AK because of these design characteristics. The 7.62x39 round has a conical shape which leads to very reliable chambering since the cartridge only makes full contact with the chamber once it is fully seated. Lastly, the AK's distinctively curved magazine plays an outsized role in the rifle's reliability because it uses an anti-tilt follower for smooth, positive ammunition feeding. Modern iterations of AR-15 magazines brag about using anti-tilt followers; however, AK magazines have always used them.
What Makes the AK47 Easy to Use?
The AK is a simple, robust design with few parts. Controls are large and easy to use with bulky gloves, a must in the harsh winter climate. Magazines positively lock into place with an audible click. AKs are straightforward to field strip for cleaning and service and require less maintenance than other rifles to achieve similar reliability.
The AK47 and its variants are the most widely produced firearms in history. One could fill vast volumes with AK's development, history, and usage. This article is meant to be an AK overview, so be sure to let me know in the comments if I missed anything.