In 1970s and early 1980s, China repeatedly discussed the possibility of independently developing sniper rifles and realizing localization, and finally decided to abolish the old Mosinnagan M 1930 non-automatic sniper rifle and imitate the Dragunov sniper rifle of the former Soviet Union.
Draganov sniper rifle copied by China was adopted by the Chinese Army in the name of "79-type 7.62mm sniper rifle" in 1979, and the Chinese Army put forward some improvement requirements for the gun during its use. According to the requirements of the military, the final model after partial improvement was adopted by the Chinese Army in 1985 and named as "Type 85 7.62mm sniper rifle". After China began to implement the reform and opening-up policy, the export types of 79-type and 85-type sniper rifles began to be exported to foreign private markets through North Industries Corporation. The overall design of China 79 sniper rifle has no support, and its appearance looks different, but its basic mechanism still adopts the design of Kalashnikov assault rifle of the former Soviet Union. The automatic mode is the traditional air guide type, and the piston barrel is located above the gun barrel; As a locking mode, the locking bolt machine is used to complete the opening and closing action through rotary motion; The bolt frame is very large, and the whole bolt is wrapped in the bolt frame; Except for the trigger, the basic shape and action mode of the firing mechanism in the case are all standard designs of AK series.
However, the Type 79 sniper rifle did not completely imitate the mechanism of AK, but made some improvements made by China alone. The biggest improvement is that while fully absorbing the advantages of AK, the magazine is skillfully combined into a stock by using an unsupported structure, and a grip is arranged in front of the magazine.
Automata has also improved a lot. As we all know, the rack, piston guide rod and piston of AK assault rifle are integrated, while these three parts of 79 sniper rifle are designed to be independent, which is equivalent to combining the air guide type and recoil utilization type into one. By designing the three parts as independent parts, the backward speed and backward energy of the gun rack are reduced, so as to prevent the backward gun rack from violently hitting the rear end of the shell and relatively reduce the recoil when launching.
In front of the piston barrel of Type 79 sniper rifle, a gas regulator with an adjustable inlet is added.
Function of gas pressure in plug cylinder. This function is not available in AK assault rifles designed as infantry equipment for the first purpose of simplification. The gas regulator can adjust the pressure of gas entering the piston barrel, which is convenient for firing bullets with different pressures and is used to eliminate the faults caused by pollution. China's new rifle family designed the gun rack, piston guide rod and piston into three independent parts, and adopted an automatic way similar to the combination of air guiding and recoil utilization. In this way, the initial pressure of the emitted gas on the piston becomes an important factor to ensure the flexible action of the bolt, so the gas regulator plays a considerable role when using bullets with different pressures.
There are many ammunition manufacturers in China, so it is difficult to say that the performance of bullets produced by different ammunition factories is completely consistent, so the gas regulator is particularly effective in stabilizing the action of rifles (even if bullets with different pressures are fired). In addition, China has a vast territory, and the temperature difference between different regions is extremely obvious. The temperature difference is accompanied by seasonal and regional differences, which can easily bring about the change of the pressure of the emitted gas, which may be one of the biggest reasons for the rifle failure. Therefore, as one of the important means to prevent and eliminate these faults, the existence of gas regulator is extremely important.
Type 79 sniper rifle is designed for high-precision sniper. In order to improve the aiming accuracy, it is almost
The large base of the optical sight is arranged above the rear of the barrel, which is also used as the contact point between the piston guide rod and the gun rack, and also used to keep the gun rack guide rod. The firing mechanism of Type 79 sniper rifle is basically the same as that of AK assault rifle, but the difference is that the hammer spring of AK assault rifle is twisted into a strand by three steel wires, which is very strong. However, the hammer spring of 79-strike rifle is only made of 1 steel wire, which is probably a special measure to avoid the disadvantage that the vibration before launching caused by strong hammer spring affects the aiming accuracy.
Because the hammer spring force becomes smaller, the possibility of fire increases. As a countermeasure, the 79-type sniper rifle cancelled the practice of installing a very thin firing pin in the bolt, but increased the overall volume and weight of the firing pin, and installed the firing pin on the gun frame to prevent accidental firing. Through this structural change, the problem of insufficient hammer spring force is made up with a striking needle with great inertia, thus achieving the purpose of preventing misfire. The bolt frame moves forward so that the bolt rotates and locks with the rear end of the barrel. Before this, the phenomenon that the striking needle protrudes in front of the bolt and causes an accident by mistake has been prevented. Although this is a very inconspicuous part, for the reference of the original AK assault rifle,
This is a great progress. Due to the unsupported design, the trigger is arranged under the barrel in front of the cartridge case. The trigger is fixed by the trigger shaft below the sight base. In order to transmit the motion of the trigger to the resistance iron, a long trigger link extends backward. This structure has caused some problems. First, the heat transfer of the trigger link. I once shot a Finnish-made and Chinese-made bareback rifle with the trigger fixed to the barrel. According to the shooting experience at that time, after firing a certain number of bullets, the heat of the barrel was transferred to the trigger, which made the trigger hot. Although it has not reached the point where it can't be touched by hand, it will inevitably affect the shooter's attention.
The trigger of the 79-type sniper rifle is wrapped in plastic. It is not difficult to see that the designer has fully realized the importance of this problem when designing the gun. But the fundamental problem is that the heat of the barrel is directly transferred to the trigger connecting rod; According to reason, it is difficult for the original long trigger link to correctly transmit the trigger action to the resistance iron, especially the trigger link that expands when heated.
The second is the worry about the loosening of the trigger shaft. The trigger of the 79 sniper rifle is fixed with a very thin shaft.
If it is fixed under the base of the sight, there will be a gap between the trigger shaft and the shaft hole during long-term use, which may make it more difficult for the trigger motion to be transmitted to the resistance iron. Type 79 sniper rifle is for safe use, and the manual safety is placed behind the magazine under the stock. The manual safety can rotate 360 degrees, and the manual safety rotates forward, so that the stop iron is locked and enters a "safe" state. The action mode of the 79-type sniper rifle is similar to the 56-type semi-automatic rifle used as a sniper rifle in China in the past, and it is also very close to the 85-type sniper rifle.
The exhausted gas enters the piston cylinder through the air guide hole on the piston cylinder, which pushes the piston to move backward at high speed; This action is transmitted to the piston guide rod, which makes the piston guide rod retreat quickly; So far, it is the same as the traditional AK assault rifle, but the action after that is different. The back end of the retreating piston guide rod collides with the front end of the gun rack, and the gun rack which is violently hit begins to retreat; Heavy self-weight bolt frame edge
Slow down the speed, retreat by inertia, rotate the bolt while retreating, and unlock the lock with the barrel; The gun rack that continues to retreat throws out the shell shell that has been fired, compresses and re-enters the spring, and retreats to the last end; During this period, compared with AK, which has a gun rack and piston guide rod as a whole, the backward speed of the gun rack of the 79 rifle with separate structure is easier to slow down. Due to the slow backward speed of the frame, it can effectively avoid the disadvantage of violent collision between the frame and the rear end of the shell, buffer the recoil and prevent the muzzle from jumping up. After that, under the tension of the compressed recoil spring, the bolt bracket began to move forward, pushing a bullet at the top of the magazine into the chamber, making the bolt rotate and locking. The first half of this automatic mode is the same as the traditional air guide mode, and the second half is equivalent to the recoil utilization mode, which is easy to slow down the backward speed of the gun rack. Type 79 sniper rifle is equipped with the same detachable 3 ~ 9 times zoom optical sight as KBU88 5.8mm sniper rifle. The name of this kind of optical sight is unknown, and the domestic data record the KBU88 type 5.8mm sniper step.
Gun sight. This zoom optical sight can gradually change the magnification in the range of 3 ~ 9 times, and the magnification can be adjusted by turning the magnification adjustment button in front of the eyepiece. There are sight zero buttons on the left and right sides in the middle of the lens barrel. When adjusting the zero point, rotate and remove these two buttons, and use a screwdriver to rotate the internal zero adjustment screw to adjust the zero point. After adjusting the zero point, aim the distance mark marked on the sight at the target and adjust the distance.
There are many inverted "V"-shaped marks on the cross line of the optical sight, and their vertices are the aiming points on the target distance indicated by the numbers on the right (unit: 100m). 1.5V battery is installed behind the base of the sight. When the switch in front of the base of the sight is turned on, the reticle in the sight emits green light, which can be used for effective sniper in the case of very dark light at night.
The sight base is directly fixed on the sight base above the rear of the lens barrel, and the mounting and dismounting of the sight can be completed by rotating the fixing rod on the left side of the sight base. This optical sight is also equipped with a metal box, which can be safely carried or transported after being removed from the gun.
In addition to the zoom optical sight used as standard equipment, the Type 79 sniper rifle is equipped with an emergency mechanical sight device considering the damage or loss of the optical sight. Both the metal ruler and the sight are folded, and when using the optical sight, they are folded down.
There is a turntable in front of the upper part of the scale. When the disk rotates, a number indicating the range will appear in the circular hole in the center behind the scale. The depth of the square notch around the disc is different, and each door has a corresponding range.
The sight is cylindrical and has a circular sight holder. The sight has the function of adjusting up and down, and the height can be adjusted by turning the sight with special tools. The special tools for rotating sight are packed together with the tools in a special accessory box, such as a combined gun wiping rod divided into 8 sections, and placed in the handle. The left and right sides of the rear upper part of the scale corresponding to the used square notch photoelectric door and the central part of the upper part of the sight are provided with fluorescent spots for aiming at night. There is no doubt that the hit accuracy when using mechanical aiming device can not be compared with that when using special optical aiming device.