Saturday, September 20, 2014

LARGE CALIBER RIFLE SR20

Desire to improve the characteristics of weapons (primarily refers to the so-called antimaterial rifles) sometimes leads to a completely unexpected and even curious results. In the early nineties, the South African company Truvelo Manufacturers launched a new family of sniper rifles for various applications, designed for the use of different weapons. "Junior" model family Truvelo SR (Sniper Rifles - «Sneyperskie rifle") was a rifle chambered for 7.62x51mm created mm NATO. Later there was a weapon cartridges .338 Lapua, 12,7h99 mm BMG and even 14,5h114 mm. However, the designers of South Africa did not stop there and created a rifle called SR20. As the name implies, this weapon had a barrel of 20 mm caliber.
 
Large-caliber rifle SR20 (South Africa)


Should make an important reservation. Receiver system 20 mm caliber and above is traditionally regarded as a small-caliber artillery. Nevertheless, there are a few samples of 20-mm weapons, which in its architecture and function are large-caliber sniper rifles. For this reason, the South African sample Truvelo SR20 can be considered as a small-caliber gun, and sniper rifle.For convenience, in what follows, we only pay attention to the proposed strategic role of these weapons and so let us call it a rifle.

As a munition designed to provide a unique high performance rifle, the designers of Truvelo Manufacturers chose 20h82 mm projectile, created in the late thirties for the German aircraft cannon MG 151/20. Probably gunsmiths staged characteristics of ammunition, as well as greater flexibility of application, as in the days of the Third Reich were created 20-mm shells five types of armor-piercing high-explosive to burst. Thus, the sniper could use ammunition that is most appropriate for a particular task. Furthermore, an advantage of the shot 20h82 mm can be considered a relatively small mass (no more than 115 g) and the relatively low initial rate (700-800 m / s) of the projectile. Due to this recoil impulse, despite the large caliber could be maintained within acceptable limits.
 
Large-caliber rifle SR20 (South Africa)
Large-caliber rifle SR20 (South Africa)


SR20 rifle had a barrel length of 830 mm to 173 mm two-chamber muzzle brake. Barrel 20 mm caliber breech had an outer diameter of 56 mm and a muzzle diameter of 35 mm. Rifling in increments of 560 mm were carried out on the technology developed by the company Truvelo. According to some reports, the barrel and chamber are in the form of individual parts.They suggested that you make out of steel of the same grade, but to quench on different technologies, so that the chamber had to have high hardness (about 40 HRC 26-33 HRC against the trunk). breech and chamber are firmly fixed in the receiver made ​​from aircraft-grade aluminum . The latter is located inside the bolt and trigger mechanism. The receiver was mounted on a cast aluminum box.


 
Large-caliber rifle SR20 (South Africa)


To simplify the design and reduce the cost of production of a sniper rifle SR20 has not received any automatic mechanisms. It was decided to use a manually operated by means of the sliding bolt. Bolt action rifle is a cylindrical piece with a distinctive spiral cut on the side intended to facilitate the construction and removal of contaminants in order to avoid disruption of the mechanisms. To facilitate the weapons in the arm gate there were several round holes. The rest of the bolt action rifle SR20 was no different from other similar units sniper systems. In cup shutter were provided extractor and reflector. The striker was made ​​adjustable. Before firing the shutter by turning the lock barrel on the two lugs. trigger mechanism of the rifle was the trigger pull adjustment system, as well as non-automatic fuse. Lever fuse is located inside the trigger guard in front of the trigger. For convenience, the SR20 rifle got an adjustable pistol grip. If necessary, the shooter could move it to the desired distance from the trigger setting in the most comfortable position. Immediately prior to the trigger guard magazine release is located. Food weapons made ​​from detachable double-row box magazine for five rounds. Selected ammunition provided a lower return when compared to other 20-mm projectiles, but its power was still too large for convenient use of weapons. In connection with this rifle SR20 received double chamber muzzle brake, the assurance of the developer gasivshy up to 60% of the recoil momentum. For high efficiency had to pay dimensions: on the trunk of the designers have established a large muzzle brake length 173, width 82 and height of 42 mm. Holes in the partitions muzzle brakes were a little more caliber bullets and had a diameter of 22 mm. On the top surface of the receiver has been provided Picatinny rail is designed to install any compatible optical sight. To design weapons had the required rigidity, and the sight is not got lost after a few shots, the bar is made ​​in one piece to the receiver. The rifle has not received any proprietary sights like the open sight.








 
Large-caliber rifle SR20 (South Africa)
Large-caliber rifle SR20 (South Africa)
Large-caliber rifle SR20 (South Africa)
Large-caliber rifle SR20 (South Africa)


The back of the aluminum box was made ​​in the form of the butt frame structure with a frame length of 170 mm. Shoulder rest butt equipped with rubber shock absorber and cushion-length adjustment mechanism. Shooter could lengthen the butt by 60 mm. Furthermore, the focus can move vertically within 40 mm from the neutral position. At the top of the butt cheek there was plastic, but as far as we know, its height does not allow you to conveniently riflescope. In front of the frame was a retractable butt additional support with up to 60 mm. At the front of the box rifle was jack is provided for the installation of a special pin. It using a clamp was installed bipod. This adaptation was performed stepwise folding and allowed to adjust the height of the line of fire. Several design features primarily associated with munitions used, impact on the dimensions and weight of the weapon. The total length of the rifle SR20 reached 1.8 meters. Weight with an eye - up to 25 kg. It is not difficult to guess how difficult could be the exploitation of these weapons. Larger dimensions and weight sniper rifle were to be a modest fee for its characteristics of fire. It has been argued that the SR20 provides an initial velocity of the projectile at the level of 710-950 m / s and can engage in effective fire at ranges up to 1500 m, and the wide range of available ammunition allows the shooter to perform many different tasks. The maximum range of 20-millimitrovoy "bullet" states at the level of 5000 m. Promotional materials stated that the rifle is capable of shooting with accuracy of fire to 1 MOA. This means that when shooting from a distance of 500 meters Rockets had to go in a circle with a diameter of not more than 145-150 mm. Several years ago, the magazine "Kalashnikov" (11/2008) published a very interesting information about the actual characteristics of the rifle SR20. Author of '"Gulliver" sniper weapon "pointed out that the examination of the rifle has a number of design flaws, as well as signs of a manufacturing defect. For example, the design and location of the fuse failed, and incorrectly drilled hole in the pin for mounting a bipod is not allowed without further adjustment to install weapons as follows.








 
Large-caliber rifle SR20 (South Africa)


Not the best performance and were weapons. During a demonstration of fire after the fifth shot has broken hammer. In this demonstration with an optical sight Nightforce NXS 5 / 5-22 × 56 in Japan, mounted on the rifle using the fastening rings.Impact appeared to be too strong for such fixtures, because of what they are for broken after three dozen shots. Finally, the poor were precision and accuracy of fire. Despite the declared parameters, while firing at 500 meters gunslinger "barely missed the 500 mm." article in the journal "Kalashnikov" completing the expected conclusion: SR20 sniper rifle at the time was "raw" and required further refinement. Since then the company Truvelo Manufacturers repeatedly participated in various exhibitions, and showed his sniper rifle. However, any new information about the "rifle-gun» SR20 missing. Probably specialists estimate developer needs the weapons market, identified the prospects of its large-caliber rifles and decided that further improvements are simply impractical. As far as we know, Truvelo SR20 rifles were produced small party and used only within the test. Any information on the supply of weapons to this model series to customers or the negotiation of the possible contracts available. based on site:





http://militaryfactory.com/

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