INSAS rifle

INSAS (an abbreviation of Indian Small Arms System) is a family of infantry arms consisting of an assault rifle, a light machine gun and a carbine. It is manufactured by the Ordnance Factories Board at Ordnance Factory Tiruchirappalli, Small Arms Factory Kanpur and Ishapore Rifle Factory. The Insas Assault Rifle is the standard infantry weapon of the Indian Armed Forces.

History

The Indian armed forces had been equipped with a copy of the Belgian FN FAL rifle since the 1950s. This copy was considered to be a distinct weapon, since its parts cannot be interchanged with either the metric or inch-pattern versions of the FAL. With the 7.62 mm semi-automatic rifle becoming obsolete in the 1980s, India began to develop the INSAS, incorporating features from several contemporary rifle designs. Although largely based on the AKM, the INSAS has a number of differences, making it a unique weapon.
During the late 1980s, the Indians expressed interest in purchasing (and possibly manufacturing under license), an East German-designed AK chambered for the 5.56x45mm cartridge.The deal ultimately fell through.
The INSAS system was originally planned to have three component weapons: a standard rifle, a carbine, and a squad automatic rifle (LMG), all chambered for 5.56x45mm NATO ammunition. In 1997 the rifle and LMG were ready for mass production, and in 1998 the first Indian army units were observed armed with INSAS rifles for the Republic Day Parade. At least 300,000 INSAS rifles are in service with the Indian army; some of these have seen action in Indo-Pakistani conflicts.

Design

The INSAS rifle is based on the Kalashnikov AK-47 action with modifications. The basic gas-operated action (long stroke gas system, rotating bolt, and stamped steel receiver) is of the Kalashnikov pattern. The gas system is fitted with a manual gas regulator similar in design to that found on the FN FAL as well as a gas cutoff. The charging handle is positioned on the left side of the forearm; it is similar in position and design to the German HK G3 rifle.
The selector/safety switch is located on the left side of the receiver above the pistol grip, which allows single shots and three-round bursts. The rifle is fitted with a side-folding carrying handle, and either a solid or side-folding metal buttstock. Furniture is made of polymer with the stock using the butt-plate from Lee-Enfield rifles. Standard magazines are made from semi-translucent polymer and contain 20 rounds. Longer 30-round magazines of similar design are available for the INSAS LMG but can also be used in the rifle. The sights consist of a hooded front, mounted on top of the gas block, and a diopter rear, mounted on the receiver cover. The flash suppressor is shaped to accept NATO-standard rifle grenades. It can be fitted with an AKM-style multipurpose knife-bayonet.
The assault rifle version has semi-auto and 3-round burst modes much like the US M16A2. Derived from the INSAS weapon systems, the INSAS Excalibur Mark-I is ergonomically designed with a folding butt and can be fitted with 20 and 30-round magazines. It is also fitted with a Picatinny rail for mounting of opto-electronic devices. The latest variant of the INSAS has semi-automatic, 3 round bursts and full automatic fire modes.
An under-barrel grenade launcher and bayonet have been recently been issued for use with the INSAS, which are also compatible with the AK-47s used by paramilitary forces

Specifications
Weight	{3.2
Length	960 mm (37.8 in), 750 mm (29.5 in) w/stock folded
Barrel length	464 mm (18.3 in)
Cartridge	5.56x45mm INSAS 5.56x45mm NATO 5.56×30mm MINSAS
Action	Gas-operated, Rotating bolt
Rate of fire	650 rounds/min
Muzzle velocity	900 m/s (2,953 ft/s)
Effective range	550 Meters
Feed system	20/30-round detachable box magazine
Sights	In-built Iron sights Plate for attaching various scopes made by Ordnance Factory Boar

Dragunov sniper rifle

The Dragunov sniper rifle (formally Russian: Снайперская винтовка Драгунова, Snayperskaya Vintovka Dragunova (SVD), literally "Dragunov's sniper rifle") is a semi-automatic sniper rifldesignated marksman rifle chambered in 7.62×54mmR and developed in the Soviet Union.
The Dragunov was designed as a squad support weapon, since according to Soviet and Soviet-derived military doctrines the long-range engagement ability was lost to ordinary troops when submachine guns and assault rifles (which are optimized for close-range and medium-range, rapid-fire combat) were adopted. For that reason it was originally named "Полуавтоматическая винтовка Драгунова" Dragunov's Semi-automatic Rifle.
It was selected as the winner of a contest that included three competing designs: by Sergei Simonov, by Aleksandr Konstantinov and by Yevgeny Dragunov. Extensive field testing of the rifles conducted in a wide range of environmental conditions resulted in Dragunov’s proposal being accepted into service in 1963. An initial pre-production batch consisting of 200 rifles was assembled for evaluation purposes, and from 1964 serial production was carried out by Izhmash.
Since then, the Dragunov has become the standard squad support weapon of several countries, including those of the former Warsaw Pact. Licensed production of the rifle was established in China (Type 79 and Type 85) and Iran (as a direct copy of the Chinese Type 79).

Design details

The Dragunov is a semi-automatic gas-operated rifle with a short-stroke gas-piston system. The barrel breech is locked through a rotating bolt (left rotation) and uses three locking lugs to engage corresponding locking recesses in the barrel extension. The rifle has a manual, two-position gas regulator.
After discharging the last cartridge from the magazine, the bolt carrier and bolt are held back on a bolt catch that is released by pulling the cocking handle to the rear. The rifle has a hammer-type striking mechanism and a manual lever safety selector. The firing pin is a "free-floating" type, and as a result, some soft-primered ammunition had the reputation of causing a "slam fire" event. Thus, military grade ammunition with primers confirmed to be properly seated is recommended for the Dragunov and its variants. This appears to have solved the "slam fire" issue. The rifle's receiver is machined to provide additional accuracy and torsional strength. The Dragunov's receiver bears a number of similarities to the AK action, such as the large dust cover, iron sights and lever safety selector, but these similarities are primarily cosmetic in nature.

Accessories

A number of accessories are provided with the rifle, including a blade-type bayonet (AKM clipped point or the AK-74 spear point bayonet), four spare magazines, a leather or nylon sling, magazine pouch, cleaning kit and an accessory/maintenance kit for the telescopic sight. Also included is a cold weather battery case with a "shirt clip", with a permanently attached cord [approximately 24" long] ending with another battery case cap that has an extension to press against the internal contact in lieu of the battery to complete the circuit. Placement of the external battery case into the shooters' clothing close to the body keeps it from freezing, using the clip ensures it remains in place. The clamp-style BIPOD attaches to machined-out reliefs near the front of the receiver, it literally grabs the two cut out areas and securely mounts with a large round sized head on the clamp bolt able to tightly attach the bipod. The legs are individually adjustable [as opposed to fixed length found on many rifles and LMG's] and can be folded and stowed in a forward position negating the need to remove the bipod before placing the rifle into the canvas carrying case. Interestingly enough, the two legs are held close together with a "J" shaped clamp attached to one leg and swung over the other leg. Original Soviet/Russian SVD bipods fetch a very high price when they rarely appear on the market.

Specifications
Weight	4.30 kg (9.48 lb) (with scope and unloaded magazine) 4.68 kg (10.3 lb) (SVDS) 4.40 kg (9.7 lb) (SVU) 5.02 kg (11.1 lb) (SWD-M)
Length	1,225 mm (48.2 in) (SVD 1,135 mm (44.7 in) stock extended / 815 mm (32.1 in) stock folded (SVDS) 900 mm (35.4 in) (SVU) 1,125 mm (44.3 in) (SWD-M)
Barrel length	620 mm (24.4 in) (SVD, SWD-M) 565 mm (22.2 in) (SVDS) 600 mm (23.6 in) (SVU)
Cartridge	7.62×54mmR
Action	Gas-operated, rotating bolt
Muzzle velocity	830 m/s (2,723 ft/s) (SVD) 810 m/s (2,657.5 ft/s) (SVDS) 800 m/s (2,624.7 ft/s) (SVU)
Effective range	800 m
Maximum range	1,300 m with scope 1,200 m with iron sights
Feed system	10-round detachable box magazine
Sights	PSO-1 telescopic sight and iron sights with an adjustable rear notch sight

Gepárd anti-materiel rifles

The Gepárd anti-materiel rifles are a family of Hungarian weapons designed to destroy unarmored and lightly armored targets. These long range, large caliber rifles have high accuracy as well as high muzzle velocity. The Gepárds originate from World War I anti-tank rifles developed by the Germans to damage armored vehicles. Since then, anti-materiel rifles fell into disuse. Heavier tanks meant thicker armor, which even the heaviest rifles could not pierce. However, in 1987 the Hungarian army sought to obtain a compact, mobile weapon that could damage lightly armored targets. The project, led by Ferenc Földi (Institute of Military Technology of the Hungarian People's Army), culminated in the creation of the Gepárds.

Description

The M1 was the first Gepárd rifle to enter service. It featured a long barrel for increased accuracy, a skeleton stock to reduce weight, and used the heavy 12.7 x 108 mm Soviet cartridge. However, the rifle was complicated to reload. The M1 fired only one shot and would then have to be manually reloaded. To do this, the user had to rotate, pull back, remove the grip assembly (whose shape resembles a signal-flare handgun), and insert another cartridge. This tedious task took time to master and slowed the weapon's rate of fire. Other difficulties such as high recoil also plagued the M1. The recoil problem was solved with the addition of a barrel that recoiled back after each shot. The design was inspired by artillery cannons, which face the same impediment. Still, the Gepárd rifles need specially made, high-strength telescopic gunsights. Improvements, such as the addition of a carrier/lafette backpack and a longer barrel, led to the M1A1 variant, but at 21 kilograms its combat weight was deemed excessive.
The M1 was essentially a sniper weapon, not primarily intended for military field application, but for anti-terrorist police and special forces' use, who operate on the "one shot, one hit" principle. The single shot action was designed to reduce the number of moving parts and allow for extreme precision, five hits out of five shots fit in a 25 centimeter radius circle at 1300 meters. Yet, the Hungarian army decided to purchase 25 rifles of the Gepárd M1 type for use as an in-the-field materiel destruction rifle, but did not purchase any of the later variants so far. Owing to the great weight of Gepárd M1, sharpshooters were instructed to abandon the entire weapon if forced to retreat quickly and only save the grip assembly for proof, rendering the gun useless.
A semi-automatic version of the M1 was later produced. Dubbing it the M2, designers reduced its barrel length and weight. An even shorter paratrooper variant dubbed M2A2 made it more favorable to airborne forces and special forces, especially because it could be fired from the hip, thanks to the advanced recoil mechanism. A fiber optic technology scope and eyepiece imaging system was developed (or at least proposed) to allow use of a hip-fired M2A2 for VIP protection purposes. Although the 12.7 mm cartridge was considered one of the most powerful, Fellegi decided it was not good enough. He then ordered the development of the M3, with a larger 14.5 mm caliber. With this new destructive capability also came increased accuracy and range, making the M3 the most popular of the Gepárd rifles.
Nevertheless, three more models were to follow. The M4 and M5 sought to become improvements on the M2, with stronger materials and better reliability. The new versions have a more rectangular look and are usually of blackened steel finish, while M1 - M3 were usually painted olive-green colour. Gepárd M5 is a bolt action rifle for military sharpshooters and weighs only 13 kilograms, while the M4 is a semi-automatic anti-materiel rifle. The massive 10-round drum magazine, so characteristic of the M2 and M3, was replaced with a straight box magazine design with a capacity for five rounds. The later M4 and M5 can fire either Russian or NATO 12.7 mm ammunition as the gun barrel is field replaceable.
Finally, the Gepárd rifle family concluded with the M6. This rifle used the 14.5 mm round, like the M3, but featured stronger parts and an improved scope. The M3 and M6 are strictly anti-materiel rifles, because while the 14.5mm round is extremely powerful, its accuracy degrades rapidly at ranges beyond 1000 meters. Its high destructive power is very efficient in taking out hovering helicopters, APCs or mobile radar stations, however.
The production history of the Gepárd was bumpy, since it was designed and prototyped at the very end of communist rule and first production runs happened during the early-1990s, as Hungarian industrial capability shrunk in the process of transformation to market economy. Early examples were assembled at the Vízgépészeti Vállalat (Hydrotechnic State Company). Production and development of Gepárd currently happens at Báthory-Épszolg Kft., which also produces the new "Szép 7.62x51mm" bolt-action sniper rifle for Hungarian army and anti-terrorist police units. This smaller, standard caliber sniper rifle owes a lot of design elements to the Gepárd, since its designer, Ferenc Szép, also participated in development of the Gepárd guns

Specifications
Weight	17.5 kg / 38.6 lbs
Length	1,570 mm / 61.8”
Barrel length	1,100 mm / 43.3”
Cartridge	12.7x108mm B32, .50 BMG 14.5x114mm (M3)
Action	M1 Single shot 12.7x108mm and .50 BMG M2 Semi-automatic 12.7x108mm and .50 BMG M3 Semi-automatic 14.5x114mm M4 Semi-automatic 12.7x108mm and .50 BMG M5 Bolt-action 12.7x108mm and .50 BMG M6 Semi-automatic 14.5x114mm
Muzzle velocity	900 m/s (.50 BMG) 860 m/s (12.7x108mm) 1000 m/sec (14.5mm).
Effective range	2,000 m
Maximum range	2,500 m
Feed system	M1 Single shot M2,M3,M4,M6 Semi-automatic 5-round M5 Bolt-action 5-round
Sights	12 x scope

The M4 carbine

The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16 rifle, all based on the original AR-15 rifle designed by Eugene Stoner and made by ArmaLite. The M4 is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.
It is a gas-operated, magazine-fed, selective fire, shoulder-fired weapon with a telescoping stock. A shortened variant of the M16A2 rifle, the M4 has a 14.5 in (370 mm) barrel, allowing its user to better operate in close quarters combat. The M4 has selective fire options including semi-automatic and three-round burst (like the M16A2 and M16A4), while the M4A1 has the capability to fire fully automatic instead of three-round burst (like the M16A1 and M16A3). The carbine is also capable of mounting an M203 grenade launcher (the M203A1 with a 9-inch barrel as opposed to the standard 12-inch barrel of the M203 used on the M16 series) as well as its successor, the M320 grenade launcher.
The M4 carbine is heavily used by the U.S military. It is eventually going to replace the M16 rifle for most combat units in the United States Army. The winner of the Individual Carbine competition might supplement the M4 carbine in U.S. Army service. This is for the US Army only while all other services will continue to use the M4 carbine and M16 rifles.

History
Following the adoption of the M16, carbine variants were also adopted for close quarters operations. The CAR-15 family of weapons served through the Vietnam War. However, these carbines had design issues. They were primarily made for close ranges, like submachine guns, and so weapons like the XM177 "Commando" series suffered at longer ranges. In 1988, Colt began work on an new carbine design called the XM4 based on their M16A2 rifle. To remedy the range problem, Colt incorporated a 14.5 inch barrel, giving the weapon greater reach than the XM177 while still being more compact than the M16. The barrel was given the improved 1:7 inch rifle twist of the M16A2 to use the heavier 62 grain M855 rounds. The extended barrel gave the XM4 the ability to mount a shortened M203 grenade launcher. In 1994, the U.S. military officially accepted the XM4 into service as the M4 Carbine to replace the M3 Grease Gun, as well as selected M9 pistols and M16A2 rifles.
The United States Marine Corps has ordered its officers (up to the rank of lieutenant colonel) and Staff Non-commissioned officers to carry the M4 carbine instead of the M9 handgun. This is in keeping with the Marine Corps doctrine, "Every Marine a rifleman." The Marines however chose the full-sized M16A4 over the M4 as its standard infantry rifle. United States Navy corpsmen E5 and below will also be issued M4s instead of the M9.

Design

The M4 and its variants fire 5.56×45mm NATO ammunition (and .223 Remington ammunition) and are gas-operated, magazine-fed, selective fire firearms with either a multi-position telescoping stock or a fixed A2 or LE tactical stock. Original M4 models had a flat-ended telescoping stock, but newer models are now equipped with a redesigned telescoping stock that is slightly larger with curvature at the end The M4 is similar to much earlier compact M16 versions, such as the 1960s-era XM177 family. Some of those visual designs are obvious in both weapons, however most of the similarities are not very noticeable.
As with many carbines, the M4 is handy and more convenient to carry than a full-length rifle. The price is slightly inferior ballistic performance compared to the full-size M16, with its 5.5" (14 cm) longer barrel. This becomes most apparent at ranges of 300 yards and beyond. Statistically, however, most small-arms engagements occur within 100 yards.[citation needed] This means that the M4 is very much an adequate weapon for the majority of troops. The marginal sacrifice in terminal ballistics and range, in exchange for greatly improved handling characteristics, is usually thought to be a worthwhile compromise. A very large proportion of US forces engagements in the recent middle-east conflicts has consisted of urban warfare, therefore justifying the choice.
While the M4's maneuverability makes it a candidate for non-infantry troops (vehicle crews, clerks and staff officers), it also makes it ideal for close quarters battle (CQB). The M4, along with the M16A4, have mostly replaced the M16A2 in the Army and Marines. The U.S. Air Force, for example, has transitioned completely to the M4 for Security Forces squadrons, while other armed personnel retain the M16A2. The US Navy uses M4A1s for Special Operations and by vehicle crews.
Some features of the M4 and M4A1 compared to a full-length M16-series rifle include:
Compact size
Shortened barrel 14.5 in (370 mm), which includes the shorter carbine gas system.
Telescoping buttstock
However, there have been some criticisms of the carbine, such as lower muzzle velocities and louder report due to the shorter barrel, additional stress on parts because of the shorter gas system, and a tendency to overheat faster than the M16A2.

Variants

Except for the very first delivery order, all U.S. military-issue M4 and M4A1 carbines possess a flat-top NATO M1913-specification (Picatinny) rail on top of the receiver for attachment of optical sights and other aiming devices — Trijicon TA01 and TA31 Advanced Combat Optical Gunsights (ACOG), EOTech 550 series holographic sights, and Aimpoint M68 Close Combat Optic (M68 CCO) being the favorite choices — and a detachable rail-mounted carrying handle. Standards are the Colt Model 920 (M4) and 921 (M4A1).
Variants of the carbine built by different manufacturers are also in service with many other foreign special forces units, such as the Australian Special Air Service Regiment (SASR). While the SASR uses weapons of essentially the same pattern built by Colt for export (Colt uses different models to separate weapons for the U.S. military and those for commercial/export purposes), the British SAS uses a variant on the basic theme, the Colt Canada (formerly Diemaco) C8SFW.


Specifications
Weight 6.36 lb (2.88 kg) empty
6.9 lb (3.1 kg) with 30 rounds
Length 33 in (840 mm) (stock extended)
29.75 in (756 mm) (stock retracted)
Barrel length 14.5 in (370 mm)
Cartridge 5.56×45mm NATO
Action Gas-operated, rotating bolt (Direct impingement)
Rate of fire 700–950 round/min cyclic
Muzzle velocity 2970 ft/sec (884 m/sec)
Effective range 500 m for a point target and 600 m for an area target
Feed system 30 round box magazine or other STANAG magazines.
Sights Iron or various optics

TAR-21

The TAR-21 (or simply Tavor) is an Israeli bullpup assault rifle chambered for 5.56×45mm NATO ammunition with a selective fire system, selecting between semi-automatic mode and full automatic fire mode. It is named after Mount Tabor, while "TAR-21" stands for "Tavor Assault Rifle – 21st Century". Since 2009, it has been selected as the standard issued weapon of the Israeli infantry. The MTAR-21 (Micro Tavor) was recently selected as the future assault rifle of the Israeli Defense Forces, and some infantry division are being issued with the rifle, replacing the bigger and standard TAR-21.
The TAR-21 uses a bullpup design, first used in bolt action rifles such as the Thorneycroft carbine of 1901. Bullpup rifles are configured in a layout in which the bolt carrier group is placed behind the pistol grip; this shortens the overall length but does not sacrifice barrel length. The TAR-21 provides carbine length, but rifle muzzle velocity. The bullpup design is also used to minimize the silhouette of soldiers and to maximize effectiveness in turning corners in urban warfare.
Design

The TAR-21 has ejection ports on both sides of the rifle so it can easily be reconfigured for right or left-handed shooters. However, this process requires partial disassembly, so it cannot be quickly reconfigured while the rifle is in use.
The TAR-21 design was created by Zalmen Shebs, with the express purpose of creating a weapon more suited to urban combat than the M16/M4 carbine. It is based on advanced ergonomics and composite materials in order to produce a more comfortable and reliable rifle. The TAR-21 is waterproof and lightweight. The weapon has a built in laser and MARS red dot sight; one of the main advantages of having a built in system is that the weapon does not have to be zeroed after each use, but the TAR-21 can also be mounted with an array of different scopes such as EOtech holographic weapon sights, night vision systems and other electronic devices.
The TAR-21 accepts standard STANAG magazines. It can also be mounted with the M203 grenade launcher. Its ambidextrous fire mode selector above the pistol grip has a semi-automatic mode and a fully automatic mode

Variants

TAR-21 – standard version intended for multirole infantry.
GTAR-21 – standard version with notched barrel, to accept an M203 40 mm under-barrel grenade launcher.
CTAR-21 – compact short barrel version intended for commandos and special forces.
STAR-21 – designated marksman version with folding under-barrel bipod and Trijicon ACOG 4× magnification sight.
MTAR-21 – see below.
Zittara – Indian locally produced version of the MTAR-21 Micro Tavor modified to use the local 5.56×30mm MINSAS cartridge manufactured by the Ordnance Factories Board.

Specifications

Weight 3.27 kg (7.21 lb) (TAR-21)
3.18 kg (7.0 lb) (CTAR-21)
3.67 kg (8.1 lb) (STAR-21)
2.95 kg (6.5 lb) (MTAR-21)
3.19 kg (7.0 lb) (TC-21)
Length 720 mm (28.3 in) (TAR-21, STAR-21)
640 mm (25.2 in) (CTAR-21)
590 mm (23.2 in) (MTAR-21)
670 mm (26.4 in) (TC-21)
Barrel length 460 mm (18.1 in) (TAR-21, STAR-21)
380 mm (15.0 in) (CTAR-21)
330 mm (13.0 in) (MTAR-21)
410 mm (16.1 in) (TC-21)
Cartridge 5.56×45mm NATO
9×19mm Para (Optional on MTAR-21) 5.56×30mm MINSAS (Optional on Zittara)
Action Gas-operated, rotating bolt
Rate of fire 750–900 rounds/min
Muzzle velocity 910 m/s (2,986 ft/s) (TAR-21, STAR-21)
890 m/s (2,919.9 ft/s) (CTAR-21)
870 m/s (2,854.3 ft/s) (MTAR-21)
885 m/s (2,903.5 ft/s) (TC-21)
Effective range 550 m
Feed system Standard 30 round Magazine
Various STANAG magazines
Sights ITL MARS with integrated laser and IR pointer, Trijicon ACOG (STAR-21), EOTech holographic sight, others available

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.