The prototype of the AK-47, the AK-46, had a separate fire selector and safety. These were later combined in the production version to simplify the design. The fire selector acts as a dust cover for the charging handle raceway when placed on safe. This prevents intrusion of dust and other debris into the internal parts. The dust cover on the M16 rifle, in contrast, is not tied to the safety, and has to be manually closed. Soviet army handbooks for AKM and AK-74 do not cover target engagement using the semi-automatic setting, and advise the use of short and long bursts (but still recommend short ones).
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.
The construction of the AK magazine is very robust with reinforced feed lips that contribute to the reliable functioning for which the design is noted. Most Yugoslavian and some East German AK magazines were made with cartridge followers that hold the bolt open when empty; however, most AK magazine followers allow the bolt to close when the magazine is empty.
Operating cycle
To fire, the operator inserts a loaded magazine, moves the selector lever off of safety, pulls back and releases the charging handle, aims, and then pulls the trigger. In this setting, the firearm 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 weapon 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 the 7.62x39mm cartridge with a muzzle velocity of 710 metres per second (2,300 ft/s). Muzzle energy is 2,010 joules (1,480 ft·lbf). Projectile weight is normally 7.8 grams (120 gr). The AK-47 and AKM, with the 7.62×39mm cartridge, have a maximum effective range of around 400 metres (1,300 ft).
