The AK-107 and AK-108 represent a significant change to the
Kalashnikov operating system originally designed in the late 1940s. 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 lower 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. When the rifle is fired, gas is tapped from the gas port to enter the gas tube, driving the bolt carrier to the rear and the counter-recoil upper rail forward. The critical timing of the reciprocating parts is accomplished by a star-shaped sprocket that links and synchronizes both components, causing both to reach their maximum extension, or null point where forces are exactly equal, at exactly the same instant. The felt recoil is therefore eliminated, enhancing accuracy and assisting control during fully
automatic fire. The travel distance of the AK-107 reciprocating parts is less than other Kalashnikov designs, so the
cyclic rate is higher at 850–900 rounds/min rather than 600 rounds/min on other AK rifles. However, as the felt recoil is virtually eliminated, the manufacturer claims that accuracy is enhanced, especially during burst fire. The AK-107 is a
selective fire weapon, with a three-round
burst capability in addition to
semi-automatic and fully automatic firing modes. The system on the AK-107 resets to three-round burst each time the
trigger is released, even if only one or two rounds were fired. External differences between the AK-107 and its predecessors are minor. They include a modified ejection port and a much thicker operating rod cover. The method of attaching the
receiver cover now involves a rotating latch in place of the traditional Kalashnikov button at the rear of the receiver cover. The
rear sight is also attached directly to the receiver cover rather than to the receiver itself and the selector has four positions instead of three.
Optical and night sights can be installed, the rifle can also accept a
40 mm GP-25 grenade launcher. The
AK-108 is a version of the AK-107 chambered in
5.56×45mm NATO. The
AK-100 series use synthetic materials such as black fiberglass-reinforced polymer for the
pistol grip and
heat shield. This material is more cost efficient and much stronger than the original
AKM/AK-74 wood furniture. the
AK-109 is a fictional variant chambered in
7.62×39mm that was built as a proof of concept off of an AK-103 and it did not function. Only one was built.
MK-107 In March 2013, Izhmash debuted a
civilian version of the AK-107/AK-108 rifle designated the
Saiga MK-107. The MK-107 features improvements over the original AK-107 design including a rounded ergonomic
charging handle, a button-style
safety above the
trigger guard,
AR-15-style pistol grip and
stock (made by
Israeli firm CAA Tactical), and full length top
picatinny rail. ==Users==