The Alexei Kalashnikov model 47 is a Soviet-era automatic carbine originally supplied to the Red Army, but used worldwide. It was the chosen weapon of the Taliban and the Somali Pirates . It evolved into many other guns of today including the RPK, AK74 and the Type 68 AKM.
Weight: 4.3 kg (9.5 lb) with empty magazine
Length: 870 mm (34.3 inches) with fixed wooden stock
875 mm (34.4 inches) with folding stock extended
645 mm (25.4 inches) with stock folded
Barrel Length: 415 mm (16.3 inches)
Cartridge: 7.62x39mm M43
Action: Gas-operated, rotating bolt
Rate of Fire: 600 rounds/min
Muzzle Velocity: 715 m/s (2,346 feet/second)
Effective Range: 300 meters (330 yards) full automatic
400 meters (440 yards) semi automatic
Feed System: 20 or 30 round detatchable box magazine.
The first automatic-rifle was the 1908 Farquhar-Hill made in the UK. While the Farquhar-Hill-18 was successful in WWI: it was introduced too late in the war (1918) to be mass produced. 
During WWI; the Russian Empire created in 1915 one of the first assault rifles that were used in battle; the Fedorov Avtomat. While very successful and popular; it was using Japanese rounds and so the USSR discontinued the production of the rifle in order to focus instead of making guns with Russian ammunition. The USSR did not consider replacing the Avtomat with a new model of assault rifle. The USSR did use this rifle in the Winter War of 1940; but this was because the USSR did not have enough submachine guns for the conflict. After the Winter War ended; the Avtomat was scrapped and replaced by newer submachine guns: most noticeably the PPSh-41.
The AK-47 design was based on the Nazi assault rifle the StG 44 (built in 1943). Although the StG 44 was one of the first successful assault rifles created, it was introduced too late into the war to help the Nazi army. Soviet troops who faced this weapon were impressed and the Soviets discovered the potential of assault rifles in combat. The design was so effective that East Germany kept the StG 44 rifle until 1962. The StG 44 has been reported to have been used in the recent Iraq War and Syrian Civil War.
Mikhail Kalashnikov was a Soviet T-34 tank gunner who was wounded in the Battle of Bryansk in October 1941. While recovering from his wounds, he overheard other Soviet soldiers mentioning that Nazi rifles were superior to Soviet rifles at that time. Kalashnikov used his injuries as the perfect excuse to leave the front lines of the war and instead invest in weapons development; eventually leading to the creation of his AK-47. The Soviets adopted it into the army, but because of censorship it remained unknown to the world for several years until it showed its impact in wars of the 1950s and 60s. The US Army needed to replace their M-14 rifles by introducing the M-16 during the Vietnam War as a result of Viet Cong riflemen outperforming the M-14 with the AK-47s supplied to the by the Soviets. Kalashnikov would later improve and alter the design of the AK-47 to create later models; AKM, AK-74, PKM and RPK. However due to the economics of Soviet communism; Kalashnikov never became rich from these inventions, although he did have a middle-class lifestyle.
Even almost seven decades after its introduction in 1947, the AK-47's durability, low production costs, and ease of use make it the most widely used and popular assault rifles in the world. Many gun experts claim that the gun rarely fails and can operate under any terrain; being covered by water, sand or mud. It takes only a few hours to master the gun and it can function without cleaning, but if it ever did need cleaning, it can be done easily compared to more advanced guns. These qualities along with its low cost and accessibility makes it the favorite gun of unskilled revolutionaries, terrorists, and criminals worldwide. It is believed that 1 out of 5 guns in the world are AK-47s or evolved from the AK-47. The large numbers of AK-47s have made them cost only $15-100 in some black markets in undeveloped nations. New AK-47s cost on average about $800 (compared to modern rifles which cost $1500 to over $2000 in the year 2018). While later models of Ak rifles have replaced the Ak-47 in many modernized countries, the AK-47 is still produced for nations with low and undeveloped military budgets.
The AK-15 is a variation of the AK-12 designed to hold 7.62 x 39: the ammunition used by AK-47s. The Russian military is currently investing in the mass production of this rifle in response to The Second Cold War.
The January 17, 1989 (Stockton) Cleveland Elementary School Shooting involved an AK-47. This led to some of the first laws in the USA intended to limit or ban assault rifles: including the 1994 Assault Weapons Ban. The debate over the legality of non-automatic and semi-automatic rifles is still controversial today.
This weapon is the most effective weapon used by the Taliban and the Somali Pirates. The IRA used the AK-47, but normally perfer to use the more accurate AR-15 ArmaLite. It was commonly used by rebels or undeveloped nations. Saddam owned a AK-47 that's covered in gold.
- A bayoneted AK-47 appears on the flag of the nation Mozambique in honor of the Mozambican War of Independence, where the AK-47 was used by the rebels. Some rebel, extremist and terrorist groups use AK-47s in their flags as well.
- The APS is a variation of the AK design specifically made to operate underwater. https://www.youtube.com/watch?v=RaJ14y_4e94
- Before the AK-47: the most common rifle in the world was the Russian Mosin–Nagant which was mass produced for both World Wars.