Military Review

Experienced small-sized machine Tkachev AO-46

Rare specimens weapons in the Soviet Union were created in an initiative order. The experimental machine AO-46 is one of such samples. In 1969, an employee of the well-known enterprise TsNIItochmash (Klimovsk town) Pyotr Andreyevich Tkachev got excited about the idea of ​​creating a prototype of a small-sized machine gun. This machine was created under a promising cartridge 5,45x39 mm, which is under development, this cartridge was considered low pulse. The model of weapons proposed by the Weaver was given the designation AO-46 (automatic weapons, 46 is the development number of small arms in TsNIItochmash). Despite the fact that the new machine was created under the automatic cartridge 5,45x39 mm, it had a very small mass. The weight of AO-46 was only 2 kg, so it could rightly be called ultralight.

This small-sized ultralight machine gun was considered as a personal defense weapon for servicemen of the so-called “second echelon”, that is, those who do not directly participate in the firing contact with the enemy. AO-46 could become a regular weapon of Soviet tank crews, missilemen, artillerymen, various auxiliary workers. The main requirements for such a weapon include compactness, the ability to open fire very quickly, and defeat targets at a distance of up to 200 meters. At the same time, the machine gun should not have prevented the soldier from carrying out his basic functions and remain easily accessible in any position.

The compact, shortened machine gun was originally designed for the promising cartridge 13МЖВ - 5,45х39 mm. Peter Tkachev developed it according to the bullpup scheme. This development was distinguished from traditional automata by a short barrel, a metal butt, which was piled up on the top of the receiver and the use of a magazine receiver as a pistol grip for fire control. Also an interesting feature of this machine was the absence of a vapor device. To maximize the simplification of the weapon design, the gases acted on the bolt carrier frame when they were withdrawn not from the barrel, but directly from the muzzle of the flame arrester. At the same time, it was possible to fire from AO-46 both in bursts and single shots. For appearance similarity with the Israeli submachine gun, he even received the name "Soviet ultrasound."

Experienced small-sized machine Tkachev AO-46

Even at the stage of preliminary design, the designer paid great attention to the ballistics of the new 5,45-mm cartridge. Tkachev noticed that during the movement of a bullet of this cartridge along the barrel bore its speed increases very quickly. Intra-ballistic calculations allowed to establish that already at a distance of half the length of the barrel the speed of the bullet exceeds 700 m / s. This allowed to seriously reduce the barrel. Even if the trunk was shortened by half at the exit, it was possible to obtain good external ballistic characteristics. Calculations and studies have shown that reducing the barrel length from 415 mm to 210 mm leads to a decrease in bullet speed of only 16% (from 880 m / s to 735 m / s) when using a new 5,45-mm cartridge.

Despite the fact that the initial speed of the bullet allowed to count on the sufficient effectiveness of such weapons, another problem appeared. When firing from a weapon with such a short barrel, a strong muzzle flame arose, which unmasked the shooter; in addition, the magnitude of the muzzle pressure had a traumatic effect on its eardrums. The specially developed muzzle attachment, which was designed as an expansion chamber of a sufficiently large volume, helped to eliminate these phenomena. With this nozzle, exhaust gases are first discharged from it through a series of side openings in the front of the barrel of the machine, and then from the muzzle of the barrel. At the same time, this nozzle is used in the automation of weapons, playing the role of the gas chamber of the vapor system.

The next step of the designer was the search for simpler solutions in comparison with the existing AK-74 machine gun. For this, he eliminated the pistol grip, its functions went to the detachable store. In order for the new machine to be conveniently held by such a “handle”, Tkachev significantly increased the slope of the store. Taking into account the alleged specifics of the use of these weapons, including the need for hidden wearing the machine during special operations, the designer went on reducing the capacity of the store by 2 times - to 15 cartridges.

The original decision to use the store as a pistol grip had its consequences. In order to reduce its width, the cartridges in the store were placed with a very large slope. The increase in slope led to a deterioration in the efficiency of the supply of cartridges. Therefore, the decision to reduce the capacity of the store pursued not only functional goals, but also purely technical ones. The designer managed to ensure reliable operation of the machine only with the 15 magazine for cartridges.

Locking the bore of the AO-46 machine gun was tough, it was made light (0,07 kg) with a butterfly valve having two locking protrusions. The rifle was equipped with a firing-type firing mechanism with a long firing stroke - 80 mm. The long stroke of the striker contributed to an increase in the dwell time of the moving parts of the machine in the front position, which, in turn, led to a decrease in dispersion and rate of fire.

AO-46 had sights, which consisted of a flip (two positions) pillar and front sight. The shoulder rest was made of metal, if necessary, it is easily folded on top of the AO-46. In this position it could be firmly fixed with a special latch, which was located in the body of the base of the sight. The translator of fire modes on this prototype machine also served as a fuse. He was a lever and had three fixed positions (shooting single bullets, automatic fire and fuse). The fire interpreter was located on the right side of the receiver directly above the trigger.

Most of the details of the experimental small-caliber machine gun AO-46, including its receiver cover, the receiver itself and the shoulder support parts were made from sheet steel by stamping. To protect the shooter’s hands from burns, the front of the receiver cover and the metal parts of the forearm were covered with special pads made of veneer. In general, this prototype weapon favorably differed non-standard, original design design of almost all of its parts and assemblies. Despite this, AO-46 has never been mass-produced.

After the new machine gun was shown to the representatives of the Grau, they opened a new competitive theme for the creation of a similar machine gun. At the same time, the Ministry of Defense gave this topic a very unusual name - “Modern”. As part of the work on this topic, Soviet designers proposed a number of interesting prototypes of shortened automata. The most elegant of them looked like an automaton I. Stechkin, who also distinguished the original design solutions. However, preference was given to the Izhevsk development of the AKS-74U, this automatic machine was put into service in the 1979 year.

Performance characteristics of AO-46:
Caliber - 5,45 mm; used cartridge - 5,45x39 mm.
Length: with butt - 655 mm, with folded butt - 458 mm.
Barrel length - 245 mm.
Weight - kg 1,95 (without store).
The initial speed of the bullet - 715 m / s.
Magazine capacity - 15 cartridges.
Firing rate - up to 700 shots / min.
Target range - to 200 m.

Information sources:—-malogabaritnyiy-avtomat-pod-patron-5,45×39-mm-(-Rossiya-
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  1. mirag2
    mirag2 19 March 2014 07: 46
    Where is the talent of ramis (rimis, rumis ...)? - it would be interesting to listen to his opinion ...
    After all, the shutter is very light? What are the consequences of using such a shutter, not a huge rate of fire?
    And what else?
    1. ramsi
      ramsi 19 March 2014 10: 52
      I’m not sure that it’s me, but in my opinion such an easy shutter is a consequence of the course on overall weight saving. In addition, it is possible that a different design of the gas outlet (from the expander-flame arrester) required a reduction in the total mass of the gate-frame pair. No more such reasons can be seen, and if the strength characteristics were not affected, then okay ... The increased rate of fire was reduced by the long stroke of the striker. Purely visually, I like the machine gun, but it was hardly convenient to hold it with one hand, well, the magazine capacity of 15 rounds is clearly insufficient
      1. mirag2
        mirag2 19 March 2014 12: 57
        You, You-You!
        Thanks for the comment.
        I have long noticed a versed person in you.
      2. Droid
        Droid 20 March 2014 10: 51
        Note. The AK74 shutter weighs exactly 72 grams. So that there is nothing unusual.
      3. anomalocaris
        anomalocaris 20 March 2014 18: 45

        The shutter may have such a mass, but the movable system weighs 4-5 times more, this is unambiguous. You see, "disassembled", the movable system must, among other things, ensure the delivery of the cartridge from the store and the locking of the barrel. This requires a certain amount of energy. It is determined by the product of half the mass by the square of the speed, for a number of reasons, the speed of the moving parts cannot exceed 5-7 m / s, respectively, the mass of the moving parts cannot be less than 150-200 g. Otherwise, the bolt will simply not push the cartridge out of the store.
        1. ramsi
          ramsi 20 March 2014 20: 38
          purely for self-education, could you please indicate the weight of the parabellum bolt group, otherwise I won’t find it?
          1. Droid
            Droid 20 March 2014 20: 54
            Unfortunately, I have neither Parabelum to weigh, nor documentation to read.
            Unlike AKS74, for which there is a "Catalog of parts and assembly units."
            1. anomalocaris
              anomalocaris 21 March 2014 03: 10
              Ramsi, as always, confuses the warm with the soft. The P08 shutter itself weighs about 50 grams, but the connecting rod, bloodworm and barrel with a receiver are also included in the mobile system of this pistol. So the total mass of the moving parts is about 300g.
              The fact that they were not able to provide reliable operation with a 30-charging magazine in the unit under discussion just speaks of the insufficient energy of the mobile system. Which, however, is quite typical for samples with the removal of gases from the muzzle.
          2. anomalocaris
            anomalocaris 21 March 2014 02: 59
            Purely for self-education, take a guide and compare the length of our 5,45x39 and the length of 9x19. Also, for a change, you can estimate the effort with which the first cartridge is pressed against the lips of the magazine in a 30-round AK magazine with a staggered arrangement of cartridges and in a single-row, 8-cartridge parabellum store. And you really will be well done if you try to figure out what details are included in the mobile weapon system with gas automatic control and with a short stroke of the barrel.
            1. ramsi
              ramsi 21 March 2014 09: 47
              in fact, I was more puzzled by the statement about the minimum weight of the bolt group; I believe that its weight and dimensions (in the limit) are limited only by strength, and the energy of the spring - by the physical ability to distort the shutter. But if so, how does coping with the delivery of a cartridge, say, AK-107? As far as I understand, there the weight of the balancer will significantly neutralize the contribution of the shutter to this matter, but an additional spring appears ...
              1. anomalocaris
                anomalocaris 21 March 2014 13: 13
                You, as always, do not understand everything correctly. In the particular case of the AK-107, the balancer also takes part in the forward movement of the mobile system, as does the shutter and, in exactly the same way, is part of the mass of the mobile system. The fact that he is moving to meet the bolt frame does not cancel this.
                1. ramsi
                  ramsi 21 March 2014 17: 56
                  What are you talking about? .. They, of course, make up a lot, but from the work of pulling the cartridge out of the store and transporting it into the barrel - they only hook, direct and lock (I'm not even sure what can be said to "send")
                  1. anomalocaris
                    anomalocaris 21 March 2014 18: 41
                    I know that arguing with you is about the same as with a wall, meaningless and useless. But still, maybe you have heard from the edge of your ear about such sciences as the theory of machines and mechanisms and theoretical mechanics? If so, then try to find a textbook and read the chapter on calculating the moments of inertia of a multi-link mechanism. Believe me, you will learn a lot of new and interesting things.
                    1. ramsi
                      ramsi 22 March 2014 08: 55
                      you are right, I’m not good at writing (yes, I can’t beat many letters), but I think that if all the designers had reasoned like you, then (in particular) there wouldn’t have been weapons with balanced automation
                      1. anomalocaris
                        anomalocaris 22 March 2014 15: 04
                        The textbook was never found, and therefore not read? Baby, how did you get me ... You know, just here the other day, one of the same asshole kicked me away.
                      2. ramsi
                        ramsi 23 March 2014 09: 20
                        I don’t know who you think you are, in my opinion - an old inflated bubble with the initial signs of insanity. Looking at dominoes? ..
                      3. anomalocaris
                        anomalocaris 24 March 2014 13: 58
                        Baby, I'm not in my soul what you think of yourself. But personally, I know about myself that I am a SOVIET hydraulic engineer, that I have wandered all over the immense, plus "near" and "far" abroad. I solved issues that the enlightened Europeans could not solve. And even more so you never dreamed of.
                        I know one thing for sure. I would give you a ride on the exam. For you do not understand nichrome in the interaction of matter.
                      4. ramsi
                        ramsi 24 March 2014 21: 14
                        I'm sorry, grandpa, I was wrong - it’s not about the initial, but about the progressive symptoms of insanity. If you are not familiar with it, then nobody cares here - people just pass the time: they learned something new - well, no - well, okay. So take care of the nerves, they will come in handy when you apply for a pension (unless, of course, you survive)
                      5. anomalocaris
                        anomalocaris 25 March 2014 16: 42
                        Baby, did you find a textbook?
  • avt
    avt 19 March 2014 09: 12
    Talented good But! Very big doubts in practical use are caused by the combination by the store of the function of holding the weapon in hands, and even in the proposed version.
    1. mirag2
      mirag2 19 March 2014 09: 49
      Yes, it's probably easy to change, the weight of only a gram will increase by 50-75.
  • Blot
    Blot 19 March 2014 10: 03
    I didn’t see anything worse !!! It sucks! The horror is disgusting!
    1. Max otto
      Max otto 19 March 2014 10: 43
      Quote: Blot
      I didn’t see anything worse !!! It sucks! The horror is disgusting!

      Yeah, but Uzi is the top of beauty and aesthetics !!! Lithuanian horse presses on the brain? laughing
    2. combat192
      combat192 19 March 2014 14: 16
      Do it better!
  • les103284
    les103284 19 March 2014 10: 27
    Good morning everyone! Quite a lot of experimental developments have remained in the storerooms of designers for all kinds of reasons. Meanwhile, both TsNIItochmash and Tula with Izhevsk have many promising developments, I believe their time will come, they will be in demand in one way or another!
  • Leader
    Leader 19 March 2014 10: 44
    Another page of our weapons history is ajar ...
    It's a pity the interiors of the device were not shown.
    1. mr.vorodis
      mr.vorodis 20 March 2014 00: 42
      Colleague, as ordered - "the insides of the device"
  • amigo1969
    amigo1969 19 March 2014 11: 17
    For "comrades" who criticize design. In these photos - concepts, working models and blanks were made .. The appearance of any weapon is finalized in the last turn .. There is a bold research of the engineer, attempts to find the optimal balance of firepower, compactness and weight .. Any experimental model of a weapon, even if it is unsuccessful and did not go into the series - it still goes to the piggy bank of gunsmiths engineers.
    1. les103284
      les103284 19 March 2014 13: 45
      I agree completely! Sometimes, the form of the content does not change (diamat)!
  • Denbfrkas
    Denbfrkas 19 March 2014 15: 22
    but I like the design will go that way.
  • Ilya Mikhalych
    Ilya Mikhalych 19 March 2014 15: 52
    A good prototype, it would be brought to mind and it will be a very convenient unit. The brainchild of an inquiring mind! Article +
  • Nova
    Nova 19 March 2014 16: 57
    Something began to repeat the site. Two years ago, here is about the same AO-46:
  • kafa
    kafa 19 March 2014 16: 57
    original but not ingenious. a lot of difficulties winked but the fact that it is difficult is not durable because it is not reliable ....
  • SIT
    SIT 19 March 2014 20: 49
    The cocking lever arm had to be made on the left and still, when reloading, the hand would have to be removed from the fire control handle, because this is a replaceable store. As a result, a lot of time to recharge. And the 5.45X39 cartridge is really long for such a lineup. Here from stg44 maybe it would fit.
  • vkrav
    vkrav 19 March 2014 21: 31
    Sooner they refused the TTsnoy cartridge ... For PP - that’s it! And so the appearance suggests that you can’t shove the non-pushable, but you must try!
  • Mikhail3
    Mikhail3 19 March 2014 22: 41
    Handsome. The design is reminiscent of the general "aircraft-missile" direction of the 60s. I bet - a limited batch would be raked in an instant, without looking at the price.
  • rostov-dad
    rostov-dad 19 March 2014 23: 07
    yeah! thing! here he would have a TT cartridge, or put a screw shop under 5,45 / 39 on top, then he would not have a price, well, he’s still handsome!
  • vkrav
    vkrav 20 March 2014 00: 16
    Quote: Rostov-Dad
    yeah! thing! here he would have a cartridge TT

    Why reinvent the wheel? Here is the CZ26 Holek - from which Blashnikov "invented" the ultrasound.
  • mr.vorodis
    mr.vorodis 20 March 2014 00: 38
    Commissioned by a colleague Vozhik - "the insides of the device"