Shotgun with the ability to conduct automatic fire AA-12.
Probably the most famous, or rather the most senior sample of the three described below, is AA-12. Rather, the name "AA-12" is the name of the last version of the gun, and before it was created many other, very different types of smooth-bore weapons, with the possibility of automatic fire. However, some of the weapons options were truly unique and rather bold. But let's start in order to understand how this weapon came into being in the form in which it now exists, and what its predecessors were, which had the right to life with more detailed elaboration.
Based on his experience of the Vietnam War, Maxwell Archisson began developing smooth-bore weapons for combat use in 1970 year. Seeing how effective a smooth-bore weapon can be at short distances and in the jungle, Atisson decided to make the gun even more formidable, giving it the power of automatic fire. Naturally, the designer did not receive the support of such a delusional idea, because for many, both then and now automatic fire from a 12-caliber gun seems delusional and suitable only for people whose strength exceeds the strength of the average person. That is, the weapons were considered “not for everyone,” and therefore they were not given rights to life. The designer did not stop neither that there was no financial assistance from the outside, nor the misunderstanding of his acquaintances, he went to the goal, and very soon he achieved his goal.
Already in 1972, the designer created the first version of the gun with the possibility of automatic fire. In his first model, the designer emphasized that his weapon was cheap to manufacture and easy to maintain, because a number of details in this gun with the possibility of automatic fire were borrowed from other weapon models that were not even worthy of guns. The rest, which could not be transferred from other models, was assembled from the simplest parts, which can be found in large quantities in any garage of the hoard owner. Thus, the receiver of the gun was made in the form of a pipe, inside it was located the shutter of the weapon, which could move practically along the entire length of the pipe, which had a length up to the back of the butt. The trigger was taken by the designer from the M1918 Browning machine gun, the barrel from the 12-caliber rifle, and the forearm from the M16А1 rifle. Ate a sample of detachable single-row stores with a capacity of 5 cartridges. In general, the weapon turned out really very simple and cheap to manufacture, but much more interesting was how it worked.
The one who is familiar with the design of the Browning 1918 machine gun of the year has probably already understood the basic principle of operation of this gun with the possibility of automatic fire. The thing is that Atchisson applied the automatic system with a free shutter, with firing from the open shutter and pinning the cartridge capsule when the shutter rolls. Thus, the designer managed to solve the main problem of such weapons, namely, too much impact when shooting. Not only did the valve have a long enough stroke, it also lost its speed on the way to the breech breech due to the fact that the powder gases pushed the cartridge to it, the speed and weight of which was enough to not only stop the bolt, but also his acceleration in the opposite direction. Thus, it turned out that some of the energy of the powder gases, which pushed the cartridge case out of the chamber, went into stopping the bolt of the weapon and sending it in the opposite direction, which significantly affected the convenience of handling the weapon.
Strong enough recoil of the weapon when conducting automatic fire also created another problem, namely, the loss of the store when firing under the influence of recoil. In order to eliminate this unpleasant moment, the designer introduced an additional element in his weapon, in the form of a guide for the store, which serves as a kind of support for him. This had a negative impact on the reload rate, as the store had to coincide with the guide, but at the same time solved the problem with the loss of stores. On the same sample, the designer tested a magazine with a capacity of 20 cartridges, made in the form of a disk.
In the end, Maxwell Archisson managed to achieve from his first sample almost perfect work, without failures. However, the problem of weapons automation system was that it was limited in the power of the ammunition, in addition, the powder charge, which were valid for use in these weapons and the weight of the projectiles varied within very narrow limits. That, naturally, was the negative moments of the weapon as a whole. Therefore, the designer abandoned the idea of creating a gun with the possibility of automatic fire with such an automation scheme and continued to search further for a solution that would be acceptable to his weapon.
The second version of the smooth-bore gun with the possibility of automatic fire was no less interesting sample. Refusing the scheme with a free gate and a shot from an open gate, the designer decided to make a weapon, relying on a proven and tested scheme with removal of powder gases from the barrel, but to lock the gate not by turning it, but using a locking wedge. The new scheme of automatic weapons operation allowed the use of much more powerful ammunition, as well as expanding the range of cartridges that can be used in weapons, even if they are mixed in the store.
A gas piston was located above the weapon barrel, which pushed the gun bolt back, a tube was placed in the hollow butt of the weapon, in which the bolt moved, compressing the return spring when moving backward and pushed forward. Locking the bore occurs when moving the locking wedge, which is engaged in engagement with the groove under the chamber, thereby locking the bore. Despite the fact that the weapon received a more omnivorous automation system, its recoil increased significantly, and not every person could conduct automatic fire from this type of rifle. The weapons were fed by all of the same stores that were developed in the design of the previous sample.
Thus, this sample was also not suitable for mass production, since the return of this weapon in the conduct of automatic fire was very high. But despite this, the designer decided to dwell on the automation system with the discharge of powder gases from the barrel as the most omnivorous, concentrating all his efforts on solving the problem of high recoil when maintaining automatic fire and he did it, however, it took a lot of time before everything was implemented in the current sample.
Up until 2000, the designer continued to work on his weapon and, eventually, he managed to create a sample that not only worked flawlessly, but also had quite a tolerable return. The main feature of the gun was the presence of two return springs of different rigidity, which interact with each other, stretching the recoil moment. This allowed not only to make the recoil of the weapon more comfortable and to significantly increase the resource of the gun. The shot is made when the barrel is unlocked.
Actually, this particular sample became known as AA-12, and the company was engaged in the production of Military Police System, so that a gun with the ability to conduct automatic fire can be safely called one of the oldest and at the same time one of the youngest guns among the samples presented.
The gun itself is completely made of steel, the plastic case, in fact, serves as something of a protective element from sand and dust penetrating the weapon and is not subjected to absolutely no stress when fired. The sights of the weapon open, adjustable, consist of the rear sight and the front sight mounted on high racks. The device is powered by detachable magazines with a capacity of 8 box-type cartridges and drum magazines with a capacity of 20 cartridges. The weight of the final result of Maxwell Archisson’s work is 4,75 kilograms. The total length of the weapon is slightly less than a meter - 965 millimeters, barrel length 457 millimeters. The rifle can be fed with 12 caliber cartridges with a sleeve length of both 70 millimeters and 76. The rate of fire of the gun when maintaining automatic fire is 360 shots per minute.
I think that the result of the designer’s work is more than worthy of respect, because a person laid out more than 20 years of his life to achieve the goal, while changing the approach to the realization of his weapon, and such devotion is a very rare phenomenon. If we talk about how successful this sample turned out to be, then it is even difficult to describe with words. Just look at how a fragile woman handles this sample or how an elderly person shoots, though not quite effectively, with one hand - all this can be found under the article in the form of a video about a gun with the possibility of automatic fire AA-12.
Shotgun Heckler & Koch CAWS with the ability to conduct automatic fire with a cut-off of three rounds.
This weapon is particularly distinguished among the samples presented in the article. The fact is that CAWS is a gun with the possibility of automatic fire with a cut-off 3 cartridge, in addition, this weapon uses not quite ordinary 12-caliber ammunition. Yes, and the development of this weapon was carried out within the framework of the program of the Ministry of Defense of the USA, so this sample is the result of the work of the best designers, although he had some problems.
In the early 80s of the last century, a program was launched in the United States, the main task of which was to create a smooth-bore 12-gauge weapon capable of using ammunition more powerful than standard 12/70 cartridges, equipped with both classic projectiles and feathered arrows from tungsten alloy. The Heckler & Koch company joined the work on the new weapon, which undertook to sell the weapon, and Winchester was assigned to deal with the ammunition. Naturally, other companies also took part in the work, it was very profitable business, but all the main work was commissioned and implemented by only two arms firms. The result of the work was a rather interesting sample, which, unfortunately, never began to be mass-produced. At the same time, both weapons and ammunition for it had already been created, but the project was frozen due to the fact that it was not possible to obtain the required results from ammunition with an arrow in a container, and this was the main focus of the program, although, in my look, closing this project was a very big mistake.
The weapon is a sample of a smooth-bore gun in a bullpup layout powered by a detachable box magazine with an 10 cartridges capacity. The cartridges themselves are somewhat different ammunition than the usual 12 caliber cartridges. Based on a sleeve of 76 millimeters long, these ammunition are designed for a more powerful powder charge, which the head of a hunting cartridge will not even have in the head. Besides the fact that the cartridge case has thicker walls, the groove has a protruding rim, the purpose of which is to strengthen the design of the sleeve, and also to make it impossible to use the cartridge in a smooth-bore sample of civilian weapons. In general, there were a lot of variants of various ammunition for this weapon, but it makes no sense to list them, since most of them did not meet the expectations, and shotgun and bullet cartridges already exist in a wide variety of variations.
The very same weapon model was built according to a not quite traditional scheme of automation with a short barrel stroke, and the barrel bore is locked when the bolt is turned by engaging it on the barrel, which allows the frame of the weapon to be unloaded. The very same scheme of automation works as follows. When fired, the bolt and barrel of the weapon are coupled together, so the powder gases, pushing the sleeve back, set in motion both the bolt and barrel, causing them to move backward together. The barrel, having a stiffer spring than the one that the slide frame has, begins to more quickly reduce the speed of movement, as a result of which the slide frame overtakes the slide-trunk group, moving backward more quickly. In the slide frame there are curly slots, which include a pin, threaded through the bolt arms. It is thanks to the interaction of these elements, the bolt begins to turn around its axis, leaving the coupling with the barrel. Thus, the barrel of the weapon slowly stops, and the bolt group continues its movement back, removing the cartridge case from the chamber. Having thrown away the spent cartridges, the bolt group continues to move, and its course is much longer than can be found in other types of weapons. This is done in order to stretch the moment of recoil, as well as reduce the rate of fire in automatic mode. While the slide group moves back, the barrel moves forward under the influence of its return spring. Everything is calculated in such a way that the barrel of the weapon is at its front end point exactly when the bolt group arrives at its extreme rear point. Thus, the weight of a moving barrel also compensates at least a little for the recoil force when shooting; something remotely resembling balanced automation is obtained. While the slide group, under the influence of the return spring, begins to move forward, a new cartridge of the weapon is removed from the magazine, and it is sent to the gun chamber. The bolt enters the breech breech and stops, while the slide frame continues its movement for some time. When the bolt carrier moves back, the pin engages through the bolt and shaped notches in the bolt frame, which causes the bolt to turn and engage in the grip with the barrel, which locks the bore of the weapon.
But this is only half the description of the automation of this weapon. The operation scheme of the short-stroke automatics is implemented for ammunition, which is more powerful than the usual 12-caliber hunting cartridges, and will not work with conventional cartridges, since there simply is not enough energy to operate the automation. Nevertheless, the designers also took care of the fact that the weapon would have the opportunity to shoot with conventional 12 / 70 and 12 / 76 ammunition. To do this, the design of weapons provides an additional scheme of automation, namely, automation, built on the use of part of the powder gases discharged from the barrel. A gas engine is installed on the moving barrel, which is included in the work if weak ammunition is used. When to work, and when not, this mechanism determines the inertial valve, which remains closed at a sufficient speed of the barrel of the weapon and opens if the speed of the rollback of the barrel is insufficient. Associated with the bolt carrier rifle gas piston, receiving a portion of the powder gases from the barrel pushes the bolt back, which leads first to turn the bolt and its release from the coupling with the barrel, and then move all the way back and compress the return spring. The barrel of the weapon may not reach its rearmost point, but in any case it will be in the forward position, when the shutter, moving back and throwing out the cartridge case, begins its movement in the opposite direction, removes the new cartridge from the chamber and rests against the breech part of the trunk. Locking is done thanks to all the same figure cutouts on the frame of the bolt and the pin in the bolt. In this rather interesting way, weapons were used to “omnivorous” ammunition; in production, this resulted in a serious amount.
Oddly enough, all this happiness with a double automation system weighs relatively little. The weight of the weapon without ammunition is 3,7-3,86 kilogram, depending on the length of the barrel, which is still the smallest weight among the smooth-bore guns with the possibility of automatic fire. The length of the weapon is equal to 762-988 millimeters back, depending on which barrel is installed in the weapon, but the barrel’s CA can be long from 457 to 685 millimeters. It feeds weapons from detachable box magazines with a capacity of 10 12 / 76 or 12 / 70 cartridges, including those munitions that are specially designed for this weapon. Due to the long stroke of the bolt group, the rifle's rate of fire is 240 rounds per minute, which has a positive effect on the control of the weapon, provided that it is not the largest weight and strong enough recoil.
As noted above, the development of these weapons was already at the final stage, when the US Department of Defense closed down the project. The main objective of the project was the use of feathered sub-caliber tungsten alloy projectiles in order to achieve the highest possible effective range of use of weapons and high accuracy. It was with these munitions that the project had problems, as they did not reach the required characteristics. In general, the project itself was interesting without these patrons. Naturally, the weapon turned out to be quite expensive in production, and it was possible not to count on the large distribution of this sample in view of its specificity, however, in my opinion, it was not worthwhile to completely collapse the development, after all, a lot of money was spent. In the end, this weapon could be deprived of the possibility of automatic fire, and give to the civilian market, along with more powerful ammunition, I think that people would be only glad to such an aggregate. Probably, the US Department of Defense has too much money, since it is so easy to start and close completely expensive projects, receiving minimal benefit from it in the form of experience accumulated by designers.
US-South Korean version of the gun with automatic fire USAS-12.
The latest model, which we consider in this article, is a sample of weapons, which was designed in the walls of a small company Gilbert Equipmnt Co. Or rather, it was designed by one of the designers, John Trevor, but he did not dare to promote his weapon alone. For quite a long time, the company was looking for production facilities to establish mass production of this gun, but no one in the United States was interested in this weapon, understanding its specificity and the fact that it would not pass to the civilian market. In Europe, the company's representatives also pointed to the door. In the end, managed to interest the South Korean company Daewoo, which not only took up the production of these weapons, but also improved them, making them more reliable and comfortable to use.
The main market for weapons became the countries of Asia, and subsequently the United States where the gun was assembled from South Korean parts. There was an attempt to push this model of a smooth-bore gun to the US civilian market as well, but the idea failed, as the Bureau of Alcohol, Tobacco and Firearms Control did not miss this model, suggesting that it should not be automatically fired. And this is the main feature of the weapon, and only due to the presence of the ability of an automatic fire a gun can you forgive some of its other disadvantages. And he has plenty of flaws. First of all it is the heaviest sample among all smooth-bore guns with the possibility of automatic fire, its weight is 5,5 kilogram. However, the large weight of the weapon makes it more manageable when maintaining automatic fire, so here you can look at both sides from all sides. Dimensions of weapons as considerable. The length of the gun is 960 millimeters with a barrel length 460 millimeters. It feeds weapons from detachable magazines with a capacity of 10 12 / 70 or 12 / 76 cartridges or also drum-type magazines with a capacity of 20 cartridges. The rate of fire from the sample is 360 shots per minute.
Interesting is that the sample is easily adaptable for firing from the right shoulder, and from the left. The weapon has duplicated controls on both sides, the shooter himself chooses the side of ejection of the spent cartridge, and the switch is carried out even without disassembling the weapon and can be made in just a second. This question designers worked from and to. The shutter handle is carried far forward, and, in fact, is not the shutter handle, but the handle of the gas piston of a weapon, it can be rearranged both on the left and on the right side. In this case, the handle is not rigidly connected with the details of the weapon and is motionless during firing. Although I would still not count on complete immobility, as anything happens and the handle that was motionless, for example due to the work hardening, can become very mobile and move along with the shutter. So it’s better not to insert your fingers under the shutter handle. Sights gun open. The rear sight is mounted on the handle for carrying weapons, on which alternative sighting devices can be mounted, the front sight is mounted on a high stand. There are no elements that would be adjusted to the anatomy of the shooter, the weapon does not have.
As is already clear from what is written above, the basis for the operation of the USAS-12 automatic rifle was a scheme using powder gases from the barrel. Speaking honestly, a lot of decisions in this weapon were “licked off” by the AA-12 gun, although what was used in AA-12 was also features of more than one weapon, so to say that something was redrawn still can not. In order to ensure a more comfortable return in firing back, the long stroke of the weapon’s shutter is used, as well as the accumulation of a pulse by the interaction of two springs of different rigidity and length. Actually, all this can be seen from the butt of the weapon, which is, at first glance, unjustified thickness. Locking the barrel of a weapon occurs when you turn the bolt and its engagement with the breech for the protrusions.
It was interesting to solve the problem of the ejection of the store when maintaining automatic fire from weapons recoil. Unlike AA-12, where the gun shop rests against the guide behind it, the gun shop is installed in a more familiar way to the USAS-12. This is facilitated by the fact that the gun itself has a decent weight, which makes the return is not so sharp, as well as the design of the gun, in which the store "sits" quite deeply into the weapon.
Generally speaking, the weapon turned out quite good. Despite the fact that it has a fairly large weight, it is much more convenient in comparison with the previous versions, since it has a lower recoil when firing in automatic mode. Plus, the South Korean company has taken care that the production of weapons was as cheap as possible and at the same time the quality of the gun did not suffer. It is also interesting that some variants of this smooth-bore gun are even equipped with bipods when using bullet cartridges, and besides bipods, a lot of things can be hung on the weapon. However, this does not make the USAS gun less specific than it is. Too big and heavy, this weapon loses its main advantage, namely, effective use in confined spaces, or rather getting into the enemy remains all the same effective, but the maneuverability of the fighter suffers and suffers very much. However, this disadvantage is inherent in all three models of smooth-bore guns with the possibility of automatic fire, which are described in this article.
In general, such a weapon, in my opinion, fully justifies its existence. The only thing that confuses is the dimensions of common samples and their weight. Apparently, not all designers understand that small dimensions are the indisputable plus of similar samples. Although it would be much more difficult to implement the same automation schemes in a more compact weapon with the preservation of tolerable recoil, the designers also tried far from all options for reducing the recoil of the weapon while maintaining automatic fire. In general, we will be waiting for new versions of this undeniably useful type of weapon, but this time such ones from which it would not be terrible to shoot. Well, I would like, of course, to see domestic developments in smooth-bore guns with the possibility of automatic fire.