AK-47
The AK-47 (shortened from Russian: Автомат Калашникова образца 1947 года, Avtomat Kalashnikova 1947 English: Kalashnikov's assault rifle, model of the year 1947) is a gas-operated assault rifle that was used in many Eastern bloc nations during the Cold War. Adopted and standardized in 1947, it was designed by Mikhail Kalashnikov and produced by Russian manufacturer Izhevsk Mechanicl Works. Mikhail Kalashnikov began imagining his weapon while still in the hospital, after being wounded in the Battle of Bryansk. He had been informed that a new weapon was required for the 7.62 x 41mm cartridge developed by Elisarov and Semin in 1943. (The 7.62 x 41 mm cartridge predated the current 7.62 x 39 mm.) Sudayev's PPS43 submachine gun was preferred to Kalashnikov's design. Compared with the auto-loading rifles used in World War II (the StG-44 aside), the AK-47 was generally more compact, with a shorter range, a smaller 7.62 × 39 mm cartridge, and was capable of selective fire. It was one of the first true assault rifles and remains the most widely used and known. More AK-47 rifles have been produced than any other assault rifle; production continues to this day.
Features
The AK-47 is simple, inexpensive to manufacture and easy to clean and maintain. Its ruggedness and reliability are legendary. 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 the precision and consistency that are required of more accurate firearms. Reflecting Soviet infantry doctrine of its time, the rifle is meant to be part of massed infantry fire, not long range engagements.
The notched rear tangent iron sight is adjustable, each setting denoting hundreds of meters. The front sight is a post adjustable for elevation in the field. Windage adjustment is done by the armory prior to issue. The battle setting places the round within a few centimeters above or below the point of aim out to approximately 250 meters (275 yd). This "point-blank range" setting allows the shooter to fire the gun at any close target without adjusting the sights. Longer settings are intended for area suppression. These settings mirror the Mosin-Nagant and SKS rifles which the AK-47 replaced. This eased transition and simplified training.
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 during the 20th century contained corrosive mercuric salts in the primers, which mandated frequent and thorough cleaning in order to prevent damage. Chrome plating of critical parts is now common on many modern military weapons.
Operating cycle
To fire, the operator inserts a loaded magazine, moves the selector lever to the lowest position, pulls back and releases the charging handle, aims, and then pulls the trigger. In this setting, the gun fires only once (semi-automatic), requiring the trigger to be released and depressed again for the next shot. With the selector in the middle position (full-automatic), the rifle continues to fire, automatically cycling fresh rounds into the chamber, until the magazine is exhausted or pressure is released from the trigger. As each bullet travels through the barrel, a portion of the gases expanding behind it is diverted into the gas tube above the barrel, where it impacts the gas piston. The piston, in turn, is driven backward, pushing the bolt carrier, which causes the bolt to move backwards, ejecting the spent round, and chambering a new round when the recoil spring pushes it back.
Disassembly
Dismantling the rifle involves the operator depressing the magazine catch and removing the magazine. The charging handle is pulled to the rear and the operator inspects the chamber to verify the gun is unloaded. The operator presses forward on the retainer button at the rear of the receiver cover while simultaneously lifting up on the rear of the cover to remove it. The operator then pushes the spring assembly forward and lifts it from its raceway, withdrawing it out of the bolt carrier and to the rear. The operator must then pull the carrier assembly all the way to the rear, lift it, and then pull it away. The operator removes the bolt by pushing it to the rear of the bolt carrier; rotating the bolt so the camming lug clears the raceway on the underside of the bolt carrier and then pulls it forward and free. When cleaning, the operator will pay special attention to the barrel, bolt face, and gas piston, then oil lightly and reassemble.
Ballistics
The standard AK-47 or AKM fires a 7.62 × 39 mm round with a muzzle velocity of 710 metres per second (2,329 ft/s). Muzzle energy is 1,990 joules (1,467 ft·lbf). Cartridge case length is 38.6 millimetres (1.5 in), weight is 18.21 grams (281.0 gr). Projectile weight is normally 8 grams (123 gr). The AK-47 and AKM, with the 7.62 × 39 mm cartridge, have a maximum effective range of around 300 meters (330 yd). For comparison, the 7.62 × 54 mm R cartridge has a projectile of 9.6–12 grams (148–185 gr), depending on the weapon, at a velocity of 818 metres per second (2,683 ft/s) for approximately 4,000 joules (2,950 ft·lbf) of energy.