Military Review

Automatic recoilless gun MK 115 (Germany)

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One of the ways to improve the combat effectiveness of aircraft during the Second World War was to increase the caliber of barrel weapons. The German Henschel Hs-129B-3 attack aircraft, equipped with a BK7.5 caliber 75 mm gun, became a record breaker in this regard. However, an increase in the caliber of the guns appropriately affected the recoil and made new demands on the strength of the aircraft. Recoilless artillery could be the solution to the problem, but a number of experiments with similar systems (in particular, the infamous projects of the Soviet designer L. Kurchevsky) called into question the very possibility of creating such weapons.


Automatic recoilless gun MK 115 (Germany)


In 1945, a few months before the defeat of Germany, the German company Rheinmetall-Borsig developed a project for automatic aviation guns MK 115 caliber 55 mm. In one gun it was proposed to combine all the best features of both traditional and recoilless artillery. Thanks to this, a promising 55-mm gun could be installed on some existing fighters. The used recoil reduction system made it possible to reduce the strength requirements of the power elements of the base aircraft.

The automatic gun MK 115 used automatic flue gas with a sliding wedge. At the bottom of the gate was a cutout, which included a locking wedge. An interesting feature of this tool was the placement of the return spring. Because of the need to place the nozzle of the flue pipe on one straight line with the barrel bore, the spring had to be moved downward relative to the axis of the gate. The basic elements of automation were also located below the chamber and the shutter.

The MK 115 automatic cannon can be easily distinguished from other weapons of this class by a characteristic venting tube. One of its ends was combined with the barrel's chamber, and the other one was brought out in the back of the gun and installed a nozzle on it. The dimensions of the receiver affected the shape of the tube: it had several bends.

On the upper surface of the barrel chamber there was a hole through which the powder gases were to enter the main exhaust pipe with a nozzle at the end. On the bottom surface, a hole was provided in the second tube connected to the gas piston of the automation. A chamber with holes in the walls required the use of original ammunition. The new 55 x 175 mm projectile received a burning sleeve with a brass tray. The latter was intended to rigidly connect the walls of the sleeve with the primer.

As is clear from the available schemes, the operation of the MK 115 automatic cannon should have been as follows. When moving forward under the action of the return spring, the bolt seizes the shell of the clip and sends it to the chamber. Having reached the extreme front position, the bolt with the help of special stops moves the part that performs the functions of the gas piston and the thrust of the locking wedge, and is fixed in this position. Next comes the ignition of the primer (according to some information, a new weapon should have used an electrical ignition system) and a shot. Powder gases disperse the projectile in a rifled barrel. In addition, after combustion of the liner, the gases flow into the two vapor pipes. The flow of gases escaping through the main tube must break through the nozzle and compensate for some of the recoil. The second stream goes to the lower tube, to the gas piston. The piston of complex shape releases the locking wedge and gives impetus to the bolt. The released bolt goes back, returns the unburned shell of the projectile to the clip, and then, under the action of the return spring, moves forward again. The shutter captures the new projectile and the cycle repeats.



The gun MK 115 turned out quite heavy and large. Weighing on the order of 180 kg, it had a total length of 3300 mm. Less than half of the total length of the gun accounted for the barrel length 24 caliber (1320 mm). Such dimensions and weight of the gun without ammunition greatly reduced the list of aircraft that could carry it. The dimensions and weight of the MK 115 can compensate for its other characteristics. Thus, the calculated rate of fire reached 300 shots per minute, and the initial velocity of the projectile, despite the discharge of a part of the powder gases, reached 600 m / s. Finally, the use of recoilless circuit has significantly reduced the recoil force. According to some reports, this parameter 55-mm gun MK 115 could be compared with German guns caliber 37 mm.

The development of the MK 115 gun ended in the first months of 1945. For obvious reasons, she did not have time to get to the front. Some sources claim that Rheinmetall-Borsig managed to assemble one or even several prototypes of a new gun, but the tests were not completed. According to other information, the MK 115 project remained on paper in view of the rapid onset of the forces of the anti-Hitler coalition.

Regardless of the actual stage of the MK 115 project as of the end of spring 1945, the prospective recoilless automatic gun could not influence the course of the Second World War. The project documentation went to the allies. The sharing of automation and recoilless systems turned out to be too complicated and therefore the further development of artillery, with the exception of a few experimental projects, went along the already beaten paths. In the future, the designers created either automatic guns of the worked-out schemes, or recoilless guns without automation.



On the materials of the sites:
http://wehrmacht-history.com/
http://raigap.livejournal.com/
http://luft46.com/
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16 comments
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  1. Vadivak
    Vadivak 24 January 2014 09: 43
    +3
    In my opinion, the priority in installing recoilless aircraft on aircraft was for the USSR.

    I-12 (ANT-23) was one of the first fighters specially designed for LV Kurchevsky's dynamo-reactive cannons. Its design began on April 1, 1929, and in November 1930 TsAGI presented a draft design of the aircraft. Technical requirements were drawn up for a heavy fighter capable of fighting an air enemy at long ranges and an altitude of up to 5000 m, armed with two 76,2 mm APCs. The shells were supposed to be filled with buckshot. On November 5, at a meeting of the NTC, several projects of the new aircraft were considered and finally approved its appearance. It was decided to build a two-boom single-seat all-metal fighter with two Jupiter air-cooled engines with 420 (525) hp each. and two-finned plumage. Kurchevsky's cannons were installed inside the beams, machined from steel pipes with a diameter of 170 mm.

    Another question is that it ended with the cessation of testing ....
  2. Alex65
    Alex65 24 January 2014 09: 48
    +1
    Thanks for the review, it’s very interesting, / at school (VUS) we weren’t told about it /
  3. rubin6286
    rubin6286 24 January 2014 10: 41
    +5
    The 75 mm aircraft cannon was installed on the German Henschel-129 attack aircraft during World War II. It is quite bulky and heavy. it made it difficult to fly at low altitudes and significantly reduced the performance of an already very mediocre aircraft. To hit a moving target, it was necessary to dive at it at an angle of about 35-40 degrees from an altitude of 2000m to 500m, then open fire and exit the dive. Shooting accuracy was low, although the scope used was considered one of the best in the world. The barrel of the gun could not withstand long-term operation, the magazine capacity was 12 shells. As a rule, after the magazine was used up, the gun on the plane was completely replaced. "Henschels" with a 75mm cannon unexpectedly proved to be effective in battles on the Soviet-German front in the spring of 1944 in Poland, when attacking tank columns not covered by anti-aircraft artillery on the march, but there were very few such aircraft and this modification did not receive mass distribution.
    1. Civil
      Civil 24 January 2014 12: 31
      +1
      You can even do a series of articles for connoisseurs, artillery aviation
    2. yehat
      yehat 24 January 2014 14: 53
      +1
      you have a distortion of the facts. it was not the cannon that made flying difficult at all, but the French engines, which were extremely unreliable and stalled, mainly just when diving and the desire to make a compact well-armored cabin (it was very cramped). After some refinement, the 2nd version of the hs-129 (44g) with modified engines was released, which was a little more reliable.
      Rudel on his Ju-87G proved that firing a gun could be quite effective.
      1. pavlo
        pavlo 24 January 2014 15: 24
        +3
        You just don’t need to drag Rudel’s fables here, he’s also a storyteller! Our identities also put guns on the attack aircraft, but the percentage was extremely low, and this was still at the training ground in calm conditions, and even more so in battle !!!
        1. yehat
          yehat 27 January 2014 13: 57
          0
          you forget how different the maneuverability of the thing and il-2
          this difference was very felt on hover.
        2. The comment was deleted.
        3. vtur
          vtur 28 January 2014 16: 24
          0
          Quote: pavlo
          Just do not drag Rudel’s fables here

          Yes, 10% of all destroyed Luftwaffe armored vehicles. The question involuntarily arises, but what, then, were the rest of the pilots of the German attack aircraft doing? I don’t want to develop this hackneyed topic about 500 tanks, 150 self-propelled guns, 4 armored trains and 800 vehicles that Rudel destroyed in 2530 (? !!) sorties ...
    3. The comment was deleted.
    4. family tree
      family tree 24 January 2014 16: 02
      +2
      Quote: rubin6286
      A 75 mm aircraft gun was installed during the Second World War on a German attack aircraft Henschel-129. Cumbersome and heavy enough.

      Nevertheless, a very interesting design, one of the first drum automatic loaders
      , the magazine's capacity was 12 shells
      or 16?
      1. badger1974
        badger1974 24 January 2014 23: 19
        0
        I immediately recall the German mg-213,
  4. fatalist
    fatalist 24 January 2014 11: 15
    0
    Quote: rubin6286
    the magazine’s capacity was 12 shells. As a rule, after the magazine was used up, the cannon on the plane was completely replaced.

    I do not understand, right in flight replaced?
  5. Sarmat1972
    Sarmat1972 24 January 2014 14: 19
    +1
    And on fotov article, is it not Yu-87 Gustav ??? with 37 mm ed. guns. The Germans tried to launch it since 1943. But the accuracy was very good. bad and therefore the plane did not bring the desired results. Maybe I'm wrong - correct.
    1. badger1974
      badger1974 24 January 2014 14: 40
      +2
      it’s like U-87g, the machine of the commander SG-2 Oberst Rudel, the aircraft with VK 3.7 turned out to be very dexterous, especially when the guns were not synchronized in the shot (not to be confused with the synchronization of the gun with the screw), the plane turned
    2. yehat
      yehat 24 January 2014 14: 56
      +1
      The aircraft itself required a very high quality piloting during the attack. Ases could, but newcomers could not cope, with those losses, newcomers were not uncommon.
    3. The comment was deleted.
  6. badger1974
    badger1974 24 January 2014 14: 55
    +1
    in aviation it is generally considered a "bad taste" to have a caliber of more than 37 mm, because as no combat vehicle armed with a huge caliber has had success, the same German -129, the same English Hurricane with 40mm winers, the same Yak-9 KK with 45mm, I wonder why the Germans did not organize the mass production of the successful 30 mm Mk-103, there was enough time
    1. yehat
      yehat 24 January 2014 15: 05
      0
      because the velocity of the shells was low and the ballistics was not suitable for attacking ground targets.
      As for large calibers, your remark is one-sided. The Yak-9K had problems, but it was still applicable with a 45mm gun and, unlike the Hurricane 2, it was much more effective.
      1. Andrey77
        Andrey77 24 January 2014 18: 24
        0
        The Yak-9K with 45mm was a very moody car and was released in a limited batch. The rejection of a large caliber was associated with a limitation in engine traction, nothing more. The ballistics of 45 mm was excellent.
        1. badger1974
          badger1974 24 January 2014 23: 05
          0
          the abolition of a large caliber above 37mm is associated with the appearance of the NURS not only in the Red Army Air Force but also among the allies, and the NS-45 destroyed not only the aerodynamic counter-component, but also the engine mount (in particular about the Yak-9kk), but the NS-37 took root, by the way MK -103 also "survived", only its analogue is now called "Def"
      2. badger1974
        badger1974 24 January 2014 23: 00
        0
        Quote: yehat
        because the velocity of the shells was low and the ballistics was not suitable for attacking ground targets.

        Are you talking about MK 103? I note that the speed of an almost half-kilogram MK-103 projectile was 700 m / s, which is much greater power than the VK 3.7 with a half-kilogram projectile at a speed of 500 m / s, and take into account the rate of fire of both, while 103 was much cheaper and simple to manufacture
    2. The comment was deleted.
  7. kafa
    kafa 24 January 2014 19: 55
    0
    here is an example of what you need to strain your head and invent wink
  8. Ivan Tarasov
    Ivan Tarasov 24 January 2014 23: 36
    +1
    Initially, the bet should have been made on the NAR line with a cumulative warhead.
    Efforts to create automatic machines with powerful ballistics should be developed in the direction of memory.
    The Hs -129 is not a bad idea, only if we consider it not as a "scrapping" of French engines, but as a full-scale production program for a two-seater attack aircraft with a 30 mm cannon and more powerful Japanese X-102 engines (1080 hp).