Dragunov
The Dragunov sniper rifle, in abbreviated form SVD, is a 7.62 mm semi-automatic sniper rifle, designed by Evgeniy Fyodorovich Dragunov in the Soviet Union between 1958 and 1963. The SVD was the first semiautomatic rifle in the world designed specifically for to be used in precision military shooting, and is common (in many of its variants) in the countries of the former Eastern Bloc. The need for a new semiautomatic precision rifle was evident between the Soviet high command in the 1950s, and in 1958 a contest was held between the Soviet arms designers for the creation of such a rifle. The first one was a gun designed by Sergei Simonov (known as SSV-58), the second was a prototype called 2B-W10 by Alexander Konstantinov and the third rifle, the SVD-137, a design by Evgeniy Fedorovich Dragunov. Intensive field tests of the rifles were carried out in a wide range of environmental conditions, which were surpassed by the Dragunov rifle. In 1963 the sniper rifle Dragunov was accepted into the Soviet Union's army arsenal. A batch of 200 pre-production rifles was manufactured to be evaluated, being produced in series since 1964 at the Izhmash Mechanical Factory. As of that date, the Dragunov was the standard sniper rifle of several countries, including those of the dissolved Warsaw Pact. This rifle is produced under license in China (Type 79 and Type 85) and Iran (as a copy of the Type 79 Chinese rifle).
The Dragunov is a semi-automatic rifle powered by the firing gases, using a piston system with short stroke. The chamber is closed by a rotating bolt (which rotates to the left) with three locking studs. The rifle has a manual gas regulator, with two positions. After firing the last cartridge of the magazine, the lock-bolt and the bolt are held in the open position by a detent that is disengaged by pulling back the cocking handle. The rifle has a hammer percussion mechanism and a manual safety-selector. Its mechanism box is made by machining to provide additional precision and resist torsion. The dragunov drawer mechanism has certain similarities with that of the AK-47, such as the large protective cover, the mechanical lift and the safe-selector. The Dragunov is powered from a curved magazine, with a capacity of 10 cartridges. The cartridges are in two rows, zig-zag.
The barrel has a slotted flame arrester. Its bore is chrome-plated to increase corrosion resistance and has 4 dextrorotatory grooves with a rotation rate of 320 mm. The grooved part of the bore is 547 mm. Subsequently, the rotation rate was adjusted to 240 mm, which slightly reduced precision when firing special sniper cartridges and mouth speed at 810 m / s. This was done to facilitate the use of tracer ammunition and anti-incendiary armor. These special bullets needed a lower rate of rotation for proper stabilization. The SVD uses the cartridges 7.62 x 54 R, with an initial speed of 1 130 m / s. The rifle accepts the old M1891 / 30 cartridge, but for precision shots it uses specially designed cartridges that were developed by V. M. Sabelnikov, P. P. Sazonov and V. M. Dvorianinov. The 7N1 cartridge has a bullet with steel jacket and air bag, steel core and a lead weight at its base for maximum terminal effect. The 7N1 was replaced in 1999 by the cartridge 7N14. This is a new cartridge specifically developed for the SVD. It has a bullet of 151 grains that travels at the same speed of 830 m / s, but has a tempered steel core pointed. The SVD can also fire cartridges with conventional bullets, tracer or anti-armor incendiary.
The Russian Army has set standards of precision that the SVD and its corresponding special ammunition must meet. Manufacturers must conduct firing tests to see if guns and ammunition meet these standards. To fulfill them, the Dragunov rifle that fires special cartridges 7N1 must not have an extreme vertical dispersion of more than 1.24 MDA when employing a barrel with a rotation rate of 240 mm and must not have an extreme vertical dispersion of more than 1, 04 MDA when using a barrel with a rotation rate of 320 mm. When using standard 57-N-323S cartridges, the accuracy of the SVD is reduced to an extreme vertical dispersion of 2.21 MDA. The extreme vertical dispersions of the SVD are established by firing 5 cartridges to a target located at 300 m. The precision of the Dragunov with special ammunition corresponds to that of the American M24 SWS rifles with M118SB cartridges (extreme vertical dispersion of 1.18 MDA) and M110 Semi-Automatic Sniper System with cartridges M118LR (extreme vertical dispersion of 1.27 MDA).
Although the rifle is lethal at distances of up to 1200 meters, it was not really intended or designed to achieve great accuracy and can reasonably only reach targets of more than 600 meters with standard ammunition, achieving a shot within an angle of 2 MDA at that distance. Primarily, due to the effects of the semi-automatic action of the SVD on the harmonics of the barrel, the precision of the rifle decreases in shots at great distances. Despite its size, it is handled with ease and was designed to be very durable. The Dragunov has ventilated two-piece handrails and a skeletal wooden head with a detachable cheek; this is disassembled when the hike and the point of sight are used. The new models have black polymer handrail and butt - the handrail is almost identical, while the butt has a different shape. The rifle also has a bayonet for melee combat, but when mounted, there is a slight change in the center of gravity, affecting its manageability and possibly also its accuracy.
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