The Russian PKP Pecheneg Machine Gun
In the late 1990s, TsNIITochMash developed the PKP machine gun, a unique weapon designed to reduce dispersion and increase cooling for rapid, sustained fire. This weapon system was called the PKP, Pulemyot Kalashnikova Pekhotniy, meaning Infantry Kalashnikov Machine Gun. The Pecheneg is named after the Pecheneg people, a Turkic tribe known for their warrior culture in southern Russia and Ukraine.
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The PKP’s cooling system, a standout feature, draws inspiration from the Lewis machine gun, a classic design that holds a significant place in the history of firearms. The cooling systems used in the PKP were first patented in 1996 and finally in the PKP patent in 2000. It utilizes air convection in two areas: the rear of the barrel, behind the gas block, uses natural air convection and forced air convection forward of the gas block. The rearward section of the barrel is ribbed to increase the surface area for thermal radiation; this is under a barrel shroud, which has four longitudinal slots at the 5 and 7 o’clock positions, two air ducts at 11 and 1 o’clock, and two at the 12 o’clock positions. Low pressure creates airflow upward around the ribbed barrel section as the barrel heats up during firing.
The carrying handle serves as a mirage cover for this portion of the barrel, preventing heat distortion from affecting the shooter’s view and ensuring the weapon’s performance remains consistent during extended use. The mirage cover plays a crucial role in maintaining the shooter’s visibility and the weapon’s accuracy, especially during prolonged firing, especially in cold temperatures.
The forward section of the barrel cooling system is from a 1996 Russian patent. It is comprised of four holes in the sides of the gas block that act as air ducks to four channels symmetrically around the barrel; under the forward section’s barrel shroud, when fired, the exhaust gases create suction to pull cool air through the channels and out through the muzzle device. The rearward section does not require the weapon to fire to create airflow, as it uses natural air convection and can sit after firing. The hot barrel radiates heat and airflow through the rear shroud, cooling the ribbed section. The forward barrel shroud of the first pattern PKP’s was a larger tube pinned to the barrel. Current production PKPs have a thinner forward barrel shroud that still features the forward cooling system.
The barrel and trunnion interface tolerances have been tightened to enhance accuracy. This improvement increases the barrel’s rigidity and eliminates any potential rocking within the trunnion. The barrel indexing lugs fit into corresponding slots, and the barrel support lugs are hardened to a hardness of 35.5 to 44 HRC. This reduces wear and eliminates slop and rotational movement. This meticulous design significantly decreases dispersion, improving accuracy and supporting the barrel when the bipod is attached near the muzzle, instilling confidence in the weapon’s precision.
The barrels are manufactured using a standard technological process involving cold radial compression of a blank made from 30KhN2MFA and 30KhN2MFA-Sh steel, used for improved thermal properties. Additionally, the barrel liner undergoes heat treatment to achieve a hardness of 38.5 to 44HRC, which enhances durability and wear resistance. Furthermore, there is a claim regarding using a proprietary local hardening process in the production of the PKP.
According to the PKP patent, the weapon’s proposed weight is between 2.6 and 3.3 lbs. (1.2 to 1.5 kg) lighter than the standard PKM machine gun with two barrels. A PKM with a spare barrel weighs 21.8 lbs. (9.8 kg). This weight reduction goal was achieved because, unlike the standard PKM, the PKP barrel is not designed to be replaced during extensive firing.
The bipod is attached near the muzzle mentioned in the patent to increase the weapon’s firing stability and improve the weapon’s accuracy. This improvement is said to increase accuracy by 1.6 to 2.5 times. Another notable feature is the effective flash hider, designed to eliminate nearly all noticeable flash when firing. This feature provides a tactical advantage by reducing the shooter’s visibility and ensuring that their vision is not impaired during low-light conditions, thus enhancing the weapon’s overall performance. The PKP shares 80% of its parts with the PKM. Its rate of fire is 600 to 800 rounds per minute, its effective range is 1,500 meters, and its maximum range is 3,800 meters.
These design approaches and materials have resulted in a successful machine gun, albeit with a 2.5-pound (1.1-kg) weight increase. The manufacturer ZID claims it can fire 600 rounds continuously without degrading the barrel, with an estimated lifespan of up to 30,000 rounds. This innovative design reduces the weapon’s dispersion, enabling more accurate and sustained or rapid-fire during combat operations.
The second most common question is about the oval cutout in the front of the receiver. According to several factory sources, this cutout was designed to improve cooling near the chamber, which helps reduce the insulation on the outer layer of the receiver. This design feature was implemented to enhance the system’s performance by improving heat dissipation and minimizing the risk of overheating during prolonged firing. While there is no specific data on how much this modification improved the system, the benefits seemed significant enough to justify its inclusion in the PKP.