AK 107/8

Type	Assault rifle
Place of origin	Russia

Designer	Youriy K. Alexandrov
Designed	1994
Manufacturer	Izhmash
Variants	AK-108

Weight	3.8 kg (8.38 lb)
Length	943 mm (37.1 in) stock extended / 700 mm (27.6 in) stock folded
Barrel length	415 mm (16.3 in)

Cartridge	5.45x39mm (AK-107) 5.56x45mm NATO (AK-108)
Action	Gas-operated, rotating bolt, BARS system
Rate of fire	850 rounds/min (AK-107) 900 rounds/min (AK-108)
Muzzle velocity	900 m/s (2,953 ft/s) (AK-107) 910 m/s (2,985.6 ft/s) (AK-108)
Effective range	500 m
Feed system	30-round detachable box magazine 60 round AK-74 compatible casket magazines
Sights	Protected front post, rear V-notch on tangent

The AK-107 is a Russian 5.45 mm assault rifle developed from the AK-100-series. It features a "balanced" operating system, similar to that used in the AEK-971. In this case, the designation AK does not indicate Avtomat Kalashnikova but Alexandrov/Kalashnikov. The revised designation indicates the incorporation of a new gas system, designed by Youriy Alexandrov, for Kalashnikov-pattern rifles.
These new rifles were derived from the AL-7 experimental rifle of the early 1970s. The AL-7 utilized an innovative balanced gas operating system known as the Balanced Automatics Recoil System (BARS) developed by Peter Andreevich Tkachev of TsNIITochMash that was first used earlier on the AO-38 assault rifle of 1965 that essentially eliminated felt recoil and muzzle rise. The system was modified by Alexandrov, then a junior engineer at Izhmash, and prototypes were produced under the designation AL-7. The AL-7 was considered too expensive for production at the time and the Soviet Army selected the AK-74 instead as the new service rifle. No further development occurred until the mid-1990s when Alexandrov, by then a senior engineer, was directed to update his design for production as a less expensive alternative to the AN-94. The new rifle differs only slightly from the original AL-7. The AK-107 receiver is not fluted and a three-round burst feature has been added. There is otherwise little difference between it and the AL-7 prototypes. The AK-107 and AK-108 represent a significant change to the Kalashnikov operating system originally designed in the late 1940s. The new rifle features a balanced system that functions along the lines of Newton's third law of motion, which states that for every action there is an equal and opposite reaction. This system uses a recoil-reducing countermass mechanism with two operating rods that move in opposite directions, thereby providing "balance". One operating rod, the upper, has a gas piston facing forward while the also has a gas piston. The gas tube at the forward end of the handguard is double-ended to accommodate the two rods. The enlarged gas tube cover of the upper handguard guides both rods in their travel.