The QSPR special silent revolver was a response to certain challenges of the Vietnam War. The troops and partisans of North Vietnam most actively used the developed network of underground tunnels, premises, etc., which could be used as shelters or for quick movement literally under the battlefield. To combat the underground facilities and their "garrisons" as part of several armies that fought on the side of South Vietnam, special units were created. The fighters of such units, who bore the nickname “tunnel rats,” were not always able to use regular army weapon and therefore needed some other means.
In 1967, the US Army formed a technical assignment for a promising sample of small arms, originally designed for underground operations. Tunnels of Vietnam were rarely wide and high, because of which the weapon for the "rats" was supposed to have small dimensions. The enemy found in the tunnel should be eliminated in the shortest possible time, which led to special requirements in terms of firepower. Finally, the special weapon should not have made a big noise: the roar of the shot could stun the shooter and attract the attention of the enemy.
Shortly after the issuance of the technical specifications, development work started. The main developers of future weapons were the Land Weapons Laboratory, which worked at the Aberdeen Proving Ground, and AAI Corporation. Together, the two organizations quickly formed the look of the future product and presented it to the customer. The army approved the proposed solutions, and soon experienced revolvers came to the test.
The analysis of the requirements showed that the required weapon should be created in the form factor of a revolver. In this regard, the project received the designation QSPR (Quiet Special Purpose Revolver - "Silent Special Purpose Revolver").
Shortly before the launch of the QSPR project, AAI offered several new ammunition for weapons of different classes that were distinguished by a minimum loudness of a shot. To reduce the noise of shooting, it was proposed to use the already known principle of locking the powder gases in the sleeve. Staying inside the liner, hot gases could not contact with atmospheric air, heat it and create a shock wave. As a result, the volume of the shot should have been drastically reduced. AAI has developed several cartridges of this kind. These products were intended for existing smooth-bore guns, a special underwater pistol of its own design, etc. Within the QSPR project, a similar cartridge was created for a special revolver.
The main element of the AAI QSPR cartridge was a steel tubular sleeve with a diameter of 10 mm. Its rear end was closed with screw end, the front one was sealed with a pop out cover. In the central channel of a relatively thick Donets, there was a miniature drummer, who was going outside. He had to interact with the primer placed inside the sleeve. The authors of the project considered that such a layout of the charge ignition means would increase the hermeticity of the cartridge and eliminate possible leakage of powder gases. Later, after the launch of mass production, it was decided to abandon its own drummer in the sleeve. It turned out that the standard capsule at the bottom of the sleeve and independently eliminates the breakthrough of gases to the outside.
A propellant powder charge of sufficient mass was to be placed at the bottom of the liner, and it was located inside the metal cup-piston. The piston during the assembly of the cartridge was installed directly on the bottom of the liner, until it stops. His head was in contact with a plastic separable tray, in which 15 tungsten cartilage masses of 0,5 were placed. When fired, the pan had to leave the weapon and unfold, after which the destructive elements flew to the target. Moving forward, the piston was braked by threading the liner at the barrel and locked the powder gases inside.
Smith & Wesson Model 29 products of various modifications. Photo Wikimedia Commons
The Land Weapons Laboratory and the AAI Corporation decided not to develop completely new weapons for the original ammunition. The QSPR revolver itself was decided to be made by some processing of serial weapons available on the market. The Smith & Wesson Model 29 double-action revolver chambered for .44 Magnum, produced since the late fifties, was taken as the basis for the special weapon. There were several modifications of such weapons, and a revolver with the shortest 3-inch barrel was used in a promising project.
To use the new role, the existing revolver should be reworked, taking into account the main features of the special cartridge. In accordance with the requirements of the new project, it was necessary to change the frame, barrel and drum. Some parts went under the replacement, while others planned to redo and return to the place.
Converted into a QSPR product, the S&W Mod.29 revolver retained its original architecture. He still had a one-piece frame and a drum that swings out to the side with a lever system. The double-acting trigger mechanism was retained, which provided drum rotation, cocking and descent with one pull of the trigger. The open trigger remained in place. The principles of the weapon's operation have not changed.
Scheme of the special cartridge type QSPR. Figure Modernfirearms.net
When remaking one revolver in another, it was decided to abandon the sighting devices. In the tunnels of Vietnam, the fighters would hardly have had to shoot long distances or aim for a long time. In this regard, the upper surface of the frame was now smooth. In practice, the scope itself turned out to be a frame indicating the direction of flight of the pallet with the grapeshot.
To ensure full compatibility with the 10-mm QSPR cartridge, the revolver received a new barrel. Instead of a standard rifled barrel with a length of at least 3 inches, it was proposed to use a smooth caliber 10 mm. The length of such a barrel was reduced to 1,375 inches (35 mm), which made it possible to drastically reduce the overall dimensions of the weapon. At the same time I had to noticeably shorten the frame. It is curious that the reduced front part of the frame with a shortened trunk actually became the only external difference between QSPR and the base Mod.29.
The revolver of the base model used .44 Magnum cartridges (10,9x33 mm R). New ammunition with gas cut-off was different in other dimensions, because of which it was necessary to remake the drum. Six chambers of the standard drum were boring in accordance with the dimensions of the new cylindrical sleeve. After such a revision, the drum could be returned to its place.
Chuck and split cartridge layout. For comparison, the coin is given in 25 cents with a diameter of 24,26 mm. Photo Zonwar.ru
Changes in the frame and barrel led to a reduction in the total length of the weapon to 170 mm. In comparison, the shortest of the Smith & Wesson Model 29 with a 3-inch barrel was about 40mm longer. The total mass of the AAI QSPR revolver with ammunition reached 1 kg. Despite this, the weapon was quite convenient to use and had to meet the customer's requirements.
The charge of gunpowder available in the sleeve accelerated the pallet with tungsten grapeshot up to speeds of the order of 220 m / s. At the same time, the total energy of the 15 damaging elements reached 180-185 J. Thus, individual cartilage, hitting the enemy, could inflict light or medium injuries. A certain spread of the fraction at a distance from the revolver increased the probability of hitting the target, and also ensured a high probability of simultaneous hit of several cartilage at once. It was expected that the lethal effect of grapeshot would be sufficient for effective combat work in underground tunnels.
For greater convenience, "tunnel rats" with a revolver QSPR was developed a special holster. The belt system provided carrying the weapon under the left hand. On the chest belt of the system were located small rectangular cartridge pouches for cartridges. Holster allows you to quickly pull the weapon or return it to its place, and the configuration of pouches simplified and accelerated reloading.
Chambers of the serial S&W, re-sharpened for the new cartridge. Photo Zonwar.ru
The first batch of AAI QSPR silent revolvers were manufactured in the middle of 1969. 10 prototypes were designed to study the new weapons in the conditions of the landfill and determine its real capabilities. We studied the combat and technical performance, as well as performance. Last but not least, testers were interested in the noise of a revolver, for which appropriate measurements were taken.
As part of the test, it was found that the QSPR cartridge with gas locking in the sleeve does not make the revolver completely silent. Weapons still made loud noises. First of all, the source of noise was the interaction of metal parts. However, at a distance of 1 m from the muzzle cut, the sound volume of the shot was 110 dB - noticeably lower than that of the base model revolver. Thus, a new type of revolver in terms of noise corresponded to small-caliber systems and was much quieter than weapons of similar calibers.
After conducting ground tests, in the middle of 1969, the 10 of existing QSPR products and a significant number of similar-named cartridges were sent to Vietnam for testing under actual conditions. For three months, soldiers of special units used these weapons in operations to detect and destroy enemy underground objects. "Tunnel rats" were able to study the work of such weapons, as well as compare them with other models of small arms, which they used before. For several months of trial operation a large amount of data was collected. In addition, the operators of new weapons have compiled a list of necessary improvements.
Preparing weapons for shooting. Photo Zonwar.ru
Already in 1970, a new phase of the project was launched. Now, the engineers of AAI Corporation and the Land Weapons Laboratory were to improve the existing design, taking into account the proposals of the military. It was at this stage that the QSPR cartridge lost its own drummer, who transmitted the impulse from the trigger to the primer. In addition, these or other improvements of the revolver itself, affecting its technical, combat or operational characteristics, were planned.
The process of modernization of the revolver continued until the 1972 year, when it was decided to stop it. By this time, the military and political leadership of the United States had made a decision in principle to withdraw from the war and to gradually withdraw troops from Vietnam. "Tunnel rats" continued their service and therefore still needed special weapons that met their special requirements, but continued development was considered impractical. The improved version of the AAI QSPR product - even in the absence of difficulties - could have appeared almost by the time of the end of hostilities. After the Vietnam War ended, such a weapon could have been left without work. As a result, the Pentagon ordered to stop work in advance.
During the development work, which lasted from 1969 to 1972 years, a certain number of prototypes were produced, probably differing from each other by different design features. The exact number of QSPR revolvers released is unknown. Different sources indicate completely different numbers. Some say that, taking into account the first batch, no more than 20-25 revolvers were made, while others say 200-250 products. Which of these numbers is closer to the truth is unknown.
Revolver AAI QSPR in a standard holster. Cartridge pouches are fixed on the chest belt. Photo Zonwar.ru
Apparently, certain concerns of the command, which in 1972 affected the decision to close the project, were fully justified. There is information according to which troop trials turned out to be the only episode in the combat career of AAI QSPR revolvers. There are no data on the use of such weapons after the end of the Vietnam War. In addition, the US Army in the future did not order new samples of this kind. The fact is that the American armed forces no longer had to deal with the enemy using narrow and close underground tunnels, which is why they no longer needed QSPR-type systems.
Special revolvers AAI QSPR did not differ in mass, which is why only a few units of such weapons have survived to our time. However, the market went towards collectors and gun lovers. Various gun shops offered their customers replica silent revolvers converted from the production S&W Mod.29. For obvious reasons, only modified revolvers, but not special cartridges, hit the civilian market.
AAI QSPR silent revolver was created as a response to the special challenge of the Vietnam War. A specialized system could well show itself in specific conditions and increase the combat effectiveness of special forces. Nevertheless, work on the project was delayed, and by the time it was expected to end, the war was supposed to end. As a result, the original sample was no longer of interest to the customer. "Tunnel rats" have not received a massive and highly effective weapon created specifically for them and taking into account the peculiarities of their work.
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