In 1943, the first intermediate cartridge of Elizarov and Semin appeared in the arsenal of the Red Army with a caliber of 7.62x39 millimeters. His appearance was the occasion for the development of new weapons for this caliber. As a result, several new models of small arms of different classes appeared: the SCS carbine, the RPM machine gun and the like. Degtyarev's machine gun (RPD) became the first model in its class, which worked with a new intermediate cartridge. Let's find out what else is caused by the popularity of this machine gun.
Prerequisites for creating
Even when the intermediate cartridge of Elizarov and Semin was at the design stage, it became clear that the weapons working with such a munition would in many respects surpass the older models, but in a number of parameters it would still lag behind them. The cartridge differs in small dimensions, which positively affects the volume of the ammunition carried by the fighter. At the same time, it shows a shorter target range. As shown by tests, a cartridge of 7.62x39 caliber allows to conduct an effective fire from a distance of no more than 800 meters. Based on the analysis of the battles, it was established that this range is quite enough for the weapon, which will be used on the battlefield of the future.
In early 1944, a competition was organized to create a machine gun for the intermediate cartridge. According to the order of the military, they wanted to get a light (relatively, of course) weapons, with the maximum capacity that the shell of Elizarov and Semyon can give. In addition, the new model was supposed to get rid of the shortcomings of its "older brothers" - machine guns DP and DPM. For the development of the competitive project, several leading weapons designers took their part: Simonov, Tokarev, Sudaev and others. Vasily Alekseevich Degtyarev also decided to take part in the competition, the machine guns of which at that time already were in service with the Red Army.
Thanks to many years of experience in the development of manual machine guns, Degtyarev suggested several variants of the new model. They were similar in gas automation, but differed in the structure of the combat system and the design of the shutter. First, Vasily Alekseevich Degtyarev proposed to use a disk store, similar to what is used in the DP machine gun and considered the prospect of creating a box store. However, a careful analysis of all options has shown that the most appropriate will be the use of tape combat.
As a result of the tests that took place in the middle of 1944, Degtyarev's machine gun, which received the designation RP-44, became the winner of the contest. The weapons were fired by a small party and sent to the army trials. The tests showed that the machine gun needs some modifications. The developer was presented with some comments and new requirements. After making changes, the weapons again went to the front, and was adopted for service. Soon the serial production of the model began, which was called "Degtyaryov's Manual Machine Gun of the 1944 Model", or simply RPD-44. Thus, it became one of the first samples of weapons for the cartridge 7.62x39. Now we will analyze the device of the RPD-44 machine gun.
The RPM machine gun is based on long-stroke reciprocating gas automatics. The scheme of automation, in general terms was borrowed from the last (at that time) versions of the DP machine gun. In particular, a gas regulator was installed in the automatics, which allowed to vary the amount of powder gas coming to the piston. The controller had three modes numbered with numbers. Under normal conditions, the controller was set to the middle mode, that is, the second mode. Mode "3" was intended for shooting from a contaminated machine gun. And the first mode, had the thinnest groove for evacuation of gases and allowed to lower the rate of fire.
Despite the fact that between the machine guns RPD-44 and DP / DPM had similar design solutions, Degtyarev's model was seriously different from its predecessors. In particular, it had a zero-developed receiver box, which consisted of a lower (main) part, and a top hinged lid. The back of the receiver was a so-called trigger frame. It was attached to the details of the USM, butt and the handle of the fire control. Inside the box is a bolt-on group. And on the front there was a fastening for the barrel and tube of the gas piston.
The Degtyarev's machine gun (RAP) was equipped with a barrel without the possibility of replacement, which became one of its most curious features. This decision was made on the basis of experience in the combat operation of the machine guns available at that time. It was revealed that when the fire is fired in short bursts, the machine gunner without overheating the barrel fires the entire ammunition. Thus, the need to use a removable barrel has disappeared. Moreover, he created a number of inconveniences both in combat and in the implementation of the march.
Locking the barrel
The locking system of the barrel was based on the work of divergent stops and reminded of a similar node in the machine gun of the DP. Nevertheless, it had a number of significant differences. The gate frame associated with the gas piston was in contact with the metal gate. In the design of the latter, a channel with a square cross section for the drummer and a pair of deep grooves on the side surfaces for combat stops fixed on the axes were provided. The spring was in the rear of the receiver and inside the front (metal) part of the butt.
When the slide frame moved forward, under the action of the spring, the bolt sent the cartridge into the chamber. When the shutter stopped at the extreme forward position, the frame moved the drummer further. As he shifted forward, he pushed apart the stops, which, entering the slots of the receiver, blocked the bolt. The subsequent movement of the drummer resulted in a shot.
Powder gases shifted the piston and the shutter frame by its pressure. Thanks to this, the drummer was displaced backwards, which made it possible to move from the place of the abutments. Thanks to the cutouts on the receiver, the stops returned to a neutral position, allowing the bolt to retreat. And the bolt, in turn, picked up the shot sleeve and, pulling it out of the chamber, brought it to the window for ejection. The ejection occurred down through the window in the receiver. Moving forward, the shutter frame triggered the feeder, which displaced the tape with the cartridge and led to the supply line a new ammunition. The handle of the shutter was located in the lower right side of the receiver and moved during the fire.
The RPD machine gun had a simple design of the USM, which allowed shooting only bursts. Pressing the trigger guard, the shooter moved the trigger lever and whisper, which led to the unlocking of the bolt frame and the shot. The fire was conducted with an open bolt. The design of the USM involved the use of a non-automatic fuse. His flag was on the right side of the receiver, above the trigger guard.
The machine gun was equipped with a wooden butt, an forearm and a pistol grip. The appliance and handle were attached to the trigger frame. The forehead was installed in front of the receiver and consisted of two wooden parts and gaskets made of metal. The forehead had an unusual shape (two notches: the lower and upper ones), which was due to the possibility of firing in two modes. It was assumed that when shooting from the shoulder, the machine gunner would hold the forearm from below, and when shooting "from the hip" - from above. In the second case, part of the load was redistributed to the shoulder due to the use of a belt.
Initially, it was assumed that to arm the RPD machine gun, ribbons would be used in round metal (100 cartridges) or square (200 cartridges) boxes. Later, from the 200-cartridge bulky boxes were abandoned. Serial models were equipped with collapsible cylindrical boxes. On the top of this box was a lid and mount for mounting on a machine gun. It was fastened under the receiver of the weapon. The cartridge belt got into the receiver through the corresponding window on its left side, and the spent section left through the same window on the right. Metal boxes for tapes were equipped with handles for transportation. For simplicity of transportation and operation, the boxes were placed in special pouches.
The RPD machine gun had the same aiming devices as the analogous weapons of that time. At the front of the receiver, above the cartridge receiving unit, was an open sight. It was designed to fire from a distance of 1 kilometer. And on the muzzle of the trunk was a fly with protection. To increase the accuracy of the fire, the machine gun was installed bipods. They were fastened immediately behind the fly cluster. The design allowed to fix them both in the folded and unfolded position.
Technical and operational characteristics of the RPD
The nominal rate of fire with the regulator in the "2" position was 650 rounds per minute. If you set the regulator to the first position, the rate of fire dropped noticeably. In practice, considering the need for recharging, the machine gunner could carry out from 100 to 150 rounds per minute. The high rate of fire was largely achieved through the abandonment of storekeeping in favor of tape.
At ranges up to a kilometer, the machine gun showed very good accuracy of shooting. Fire on air targets was advisable to conduct from a distance of not more than 500 meters. Bullets retained their lethal action at more serious distances, but problems arose with aiming and finding targets. When firing a burst from a distance of 100 meters, 75% of the bullets fell into a circle with a diameter of 200 mm. And the average point of impact deviated from the point of aiming by no more than 50 mm. In practice, this indicated that, for an average target of 100 meters, an average of two shots was sufficient to hit the target. To hit the same target with the maximum aiming distance, it was necessary about 27 rounds from the RAP. Shooting from a machine gun showed that it can effectively hit various targets at a distance of up to 800 meters. Thus, it fully met the requirements of the customer.
Incomplete disassembly of the RPD takes place by analogy with the DP: the fire control handle and the butt are removed, and then the inner part is removed.
Since 1946, this type of weapons began to be used together with the RP-46 machine guns, which were intended for use at the company level. Due to two new weapons, the material part of the infantry was upgraded and its firepower increased.
Later, a modernized version of the machine gun appeared, which was given the name of the RPMM. It practically did not differ from the base one. Changes affected the shape of the gas piston and its support. The handle of the bolt has ceased to be connected with the shutter frame and remained stationary during the shooting. In view of the absence of major changes at the same level, the shooting characteristics of the RAP remained.
The 7.62 caliber machine gun was actively exploited until the sixties, when a more advanced Kalashnikov machine gun was created. After the appearance of the new model, the RAPs were sent to warehouses. The Kalashnikov model had a number of advantages, including those related to the unification of production.
Having provided its army with new weapons, the defense industry of the USSR began to produce RAP weapons for export. Models were also sold, taken off the armament or kept in storage. Machine guns were delivered to more than three dozen countries in Asia, Eastern Europe and Africa. In the mid-fifties, as a friendly aid, the USSR handed over a license for the release of the RAP to China. Chinese models are called "Type 56". Later, China also began selling them to third countries.
To date, around the world can count about 40 states that legally used the Degtyarev machine gun and its Chinese versions. The machine gun participated in various armed conflicts.
Experimental samples and the first serial copies of the RAP had time to take part in the Second World War. The first conflict in which these weapons were massively used was the war in Korea. Then the RPM machine guns were used almost in all conflicts taking place in Asia and Africa.
To date, in virtually all countries where this machine gun was in service, he went into the reserve. However, there are armies that still use it. Other countries, including Russia, have replaced the RPD with a new weapon, but continue to store a number of copies in warehouses. This indicates that Degtyarev's machine gun is still valued, even a bit old.
Over time, this type of weapons began to be used not only in military affairs, but also in the civil sphere. In countries where the law does not prohibit the use of weapons by civilians, the RPM machine gun is sold to amateur gunners. For example, in the American market there are several versions of the RAP with the converted USM. He admits shooting only single projectiles. Weapons correspond to modern trends in terms of "body kit". It is equipped with numerous Pikatinni slats, telescopic butts and sights. Since the production of the RPD has long been discontinued, tunnels are subjected to models that have come off the assembly line decades ago.
The most eloquent response to Degtyarev's machine gun is the fact that it has been used in various countries of the world for several decades. He was the first domestic manual machine gun, designed for an intermediate cartridge 7.62x39. Nevertheless, the RAP showed that the first pancake is not always lumpy. Over time, the machine gun is obsolete, and this is perfectly normal. However, there are countries where it is still in service. Probably, the exploitation of these weapons will continue for several decades.