Military Review

German armor-piercing: Sverdlovsk studies of 1942


3,7-cm PaK 36. Source:

Topic #39

Sverdlovsk. 1942 year. TsNII-48 is studying captured artillery shells in application to the penetrating action on domestic tanks... It was not the only organization involved in detailed studies of the lethality of German artillery. The Artillery Committee of the Artillery Directorate, the Main Armored Directorate and the Main Intelligence Directorate of the Red Army, to one degree or another, contributed to the research. Separately, the design bureau of plant No. 112 (Krasnoe Sormovo) worked, where, among other things, options for additional armor for the T-34 were worked out. Based on the numerous data collected by 1942, TsNII-48 in Sverdlovsk issued a secret report on topic No. 39 "Study of the penetrating action of German captured shells on the armor of our tanks and the development of measures to combat them." At the very beginning of the material, we are talking about the various types of shells used by the Germans against domestic armored vehicles, and about high penetrating action. It is for these reasons that all studies of Hitler's shells in the Soviet Union received high priority status.

German armor-piercing: Sverdlovsk studies of 1942

A sketch of one of the researchable 37-mm shells. Source: 1942 Report

German infantry and motorized formations, according to intelligence in 1942, possessed solid anti-tank artillery with a large selection of calibers. Soviet engineers conditionally divided German guns into three classes: the first with a caliber of up to 37 mm, the second - from 37 to 75 mm inclusive, and the third - more than 75 mm. In this classification, 22 types of artillery guns were counted, which included the captured Czechoslovak 37-mm anti-tank guns M-34 and 47-mm Skoda guns, as well as 47-mm Puteaux anti-tank guns of the 1937 model. It is noted that the Wehrmacht also uses a 7,92-mm anti-tank rifle and even a 15-mm Czechoslovak heavy machine gun on armored vehicles. Despite such a wide arsenal, the Germans mainly used 37 mm and 50 mm calibers against Soviet tanks - simply because of the greater prevalence of these guns. With them, we will begin the story about the adventures of captured ammunition in the depths of the Soviet rear.

47-mm anti-tank gun Puteaux. One of the weapons that the Germans inherited in France. Source:

German armor-piercing 50 mm shell. Source: 1942 Report

Initially, the shells were freed from the cartridge case and discharged. In 37-mm armor-piercing tracer shells, one could find 13 grams of phlegmatized pentaerythritol tetranitrate (PETN), which is quite sensitive to impacts. The fuses were usually bottom slow action. In the Czechoslovak 37-mm shells, TNT was occasionally used. The German armor-piercing tracer sabot projectile of the 1940 model did not have explosives at all, had a weight reduced to 355 grams and an initial speed of 1200 m / s. After the projectile was gutted from explosives, it was cut along the axes of symmetry to remove a sketch and measure the hardness in different places. The first was a sharp-headed 37 mm armor-piercing projectile. As it turned out, the body of the projectile was uniform, turned from a solid forging of high-carbon chromium steel. At the same time, German gunsmiths specially hardened the head part for hardness up to 2,6-2,7 Brinell. The rest of the hull was more pliable - the hole diameter was up to 3,0 Brinell. A detailed analysis of the chemical composition of the alloy of the armor-piercing projectile showed the following "vinaigrette": C - 0,80-0,97%, Si - 0,35-0,40, Mn - 0,35-0,50, Cr - 1,1% (main alloying element), Ni - 0,23%, Mo - 0,09%, P - 0,018% and S - 0,013%. The rest of the alloy was iron and trace amounts of other impurities. A much more effective 37-mm APCR projectile, more precisely, its core, consisted of W - 85,5%, C - 5,3% and Si - 3,95%.

37-mm sub-caliber. Source: 1942 Report

These were classic German coils, which, however, made a certain impression on the domestic testers. The high-hardness tungsten carbide core of the 37-mm projectile had a diameter of 16 mm and a high specific gravity with an overall lightening of the ammunition. Tests have shown that at the moment such a projectile hits the armor, the coil sump crumples, being a kind of mandrel for the core, allowing it to penetrate the armor. Also, the pallet or coil, as the testers called it, ensured the core from premature destruction. The reel-to-reel shape of the projectile itself was chosen solely to save weight and was made of relatively mild steel with a hardness of up to 4-5 Brinell. The sub-caliber projectile was very dangerous, primarily for medium-hard armor, which was equipped with heavy domestic KV. When faced with the high-hardness of the T-34 armor, the fragile tungsten carbide core had a chance to simply collapse. But this coil shape also had its drawbacks. Initially, a high speed of up to 1200 m / s, due to the imperfect aerodynamic shape, quickly faded along the trajectory and at long distances the shooting was no longer so effective.

Caliber grows

Next in line are 50-mm shells. These were larger ammunition, the weight of which could reach two kilograms, of which only 16 grams fell on the phlegmatized heating element. Such a sharp-headed projectile was heterogeneous in its structure. Its warhead consisted of high-carbon steel with a hardness of 2,4-2,45 Brinell, and the main body of the projectile was softer - up to 2,9. Such heterogeneity was achieved not by specific hardening, but by simple welding of the head part. The report indicated that this arrangement of the armor-piercing projectile ensured high penetration in homogeneous armor and especially in high hardness armor, which was the protection of the T-34. In this case, the place of contact welding of the projectile head is a localizer of cracks formed upon impact on the armor. Before the war, TsNII-48 specialists tested similar German shells against domestic homogeneous plates and knew firsthand about the characteristics of enemy ammunition. Among the trophy armor-piercing shells were also reel-to-reel sabot. Chemical analysis of the cores of such 50-mm ammunition showed that there are differences with 37-mm counterparts. In particular, in the tungsten carbide alloy there was less W itself - up to 69,8%, as well as C - up to 4,88% and Si - 3,6%, but Cr appears in a minimum concentration of 0,5%. Obviously, it was costly for the German industry to produce expensive cores with a diameter of 20 mm using the technologies used for 37-mm APCR shells. If we return to the composition of steel of conventional sharp-headed 50-mm armor-piercing shells, it turns out that it does not differ much from its younger counterparts: C-0,6-0,8%, Si - 0,23-0,25%, Mn - 0,32 , 1,12%, Cr - 1,5-0,13%, Ni - 0,39-0,21%, Mo - 0,013%, P - 0,018-0,023% and S - XNUMX%. If we talk about saving the Germans already in the first years of the war, then it is worth mentioning the leading belts of shells, which were made of steel, although the technology required copper.

50-mm sub-caliber German armor-piercing projectile. Source: 1942 Report

A novelty of its time: a 50-mm shell with an armor-piercing tip. Source: 1942 Report

Subcaliber shells appeared in Germany in 1940. The domestic military probably had some fragmentary information about them, but the meeting with shells equipped with armor-piercing tips came as a surprise to everyone. Such a 50-mm projectile appeared already during the war and was intended directly for the sloping high-hardness armor of Soviet tanks. The ammunition had a high hardness welded head, on which an armor-piercing tip of chromium steel with a hardness of up to 2,9 Brinell was put on top. As they say in the report:

“The tip is attached to the projectile head by soldering with low-melting solder, which makes the connection of the tip to the projectile quite strong.”

The presence of an armor-piercing tip increased the effectiveness of the action of an armor-piercing projectile, on the one hand, due to the preservation from destruction, the projectile came to life at the first moment of impact on high hardness armor (read: T-34 parts), on the other hand, it increased the ricocheting angle. When hit at large angles (more than 45 degrees) from the normal, the tip “bites” the armor, as it were, helping the projectile to normalize to the plate under the action of the resulting force pair. Simply put, the shell turned slightly on impact and attacked the tank at a more comfortable angle. At TsNII-48, these conclusions were also confirmed by shelling the armor of Soviet tanks in laboratory conditions.

After careful research of 37-mm and 50-mm projectiles of various designs, test engineers began field firing. To do this, the resources of two training grounds were attracted: the Sverdlovsky training ground of the artillery plant No. 9 and the Gorokhovetsky artillery scientific testing experimental ground (ANIOP) in the village of Mulino. The organizers were specialists from TsNII-48 and the Artillery Committee of the Artillery Directorate of the Red Army. For this work, high-hardness armor plates with a thickness of 1942 mm, 35 mm and 45 mm, as well as an average hardness with a thickness of 60 mm, 30 mm and 60 mm, were prepared in 75. In the first case, the protection of the T-34 tank was imitated, in the second - the KV.

To be continued ...
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  1. Bormanxnumx
    Bormanxnumx 9 September 2020 18: 12
    In Brinell hardness values, the comma should be moved two digits to the right.
    1. Mavrikiy
      Mavrikiy 9 September 2020 18: 32
      for hardness up to 2,6-2,7 Brinell.

      Quote: BORMAN82
      In Brinell hardness values, the comma should be moved two digits to the right.

      The author got carried away and stupidly indicates the diameter of the ball's imprint, which is pointless, because the diameter of the balls is not known. Conversion to Brinell hardness scale is required.
      Carbide balls of 1 diameter are used as indenters; 2; 2.5; 5 and 10 mm
    2. psv2008
      psv2008 13 September 2020 07: 42
      The author indicates the diameter of the print according to Brinell. The conversion table for Rockwells, Vickers and Shors is online. IMHO everything is clear from the text
    3. Bobik012
      Bobik012 15 November 2020 23: 21
      No. The print diameter is given here, not the hardness index. You can see that soft materials have more of it. Converts easily enough
  2. polpot
    polpot 9 September 2020 18: 12
    Thank you, I wonder, we look forward to continuing.
  3. The leader of the Redskins
    The leader of the Redskins 9 September 2020 18: 16
    I read from the first to the last letter. Very interesting. Thank. I look forward to continuing.
    1. antivirus
      antivirus 9 September 2020 19: 48
      antivirus 2 Today, 19:36 ↑
      On the issue of starched shirts and honor.
      Yakov Mikhailovich Glazunov, captain of the Volga Shipping Company, brother-in-law of my acquaintance, b.
      “They call him, in the summer, to the shipping company’s department, to Gorky (perhaps Kuibyshev?), They say:
      - "go to Stalingrad, everyone who can be evacuated there"
      Loaded at the pier. A raid began, they were quickly kicked out of the pier.
      He went along the shore.
      - "If you get, then swim to the shore, and others who survive"
      And the second ship went in the middle and drowned,
      children injured.
      They laid out white sheets with red crosses on the deck.
      "The fascist threw, threw, but missed. I kept dodging, and left."
      "Every time I spoke with a cry"

      the same acquaintance - from Priokskoye to Navashino and further along the branch to Kulebaki under the southern slope lay tanks, cannons and scrap for melting

      people lived richly on tungsten and nickel
      1. Pavel57
        Pavel57 9 September 2020 21: 20
        It's good that there was no uranium yet.
  4. Mavrikiy
    Mavrikiy 9 September 2020 18: 18
    Material Hardness
    Soft wood, e.g. pine 1,6 HBS 10/100
    Hardwood 2,6 to 7,0 HBS 10/100
    Low pressure polyethylene 4,5-5,8 HB [1]
    Polystyrene 15 HB [1]
    Aluminum 15 HB
    Copper 35 HB
    Dural 70 HB
    120 HB mild steel
    Stainless steel 250 HB
    Glass 500 HB
    Tool steel 650-700 HB
    Do you insist that the Germans made the head part of the shells from wood?
    1. vetal1942
      vetal1942 9 September 2020 20: 14
      Well, why are you so right away, it is clear that you measured with a 10mm ball ... 2,4-2,5 print -600-650HB ...
      1. Mavrikiy
        Mavrikiy 9 September 2020 21: 49
        Quote: vetal1942
        Well, why are you so right away, it is clear that you measured with a 10mm ball ... 2,4-2,5 print -600-650HB ...

        That's just the point. The 10 mm ball is used for soft metals. It does not penetrate into hardened metal. request
        1. Bobik012
          Bobik012 15 November 2020 23: 28
          It seems to me that it is very problematic to measure the hardness of 650 - 700 HB by the brinell method. The fact that above HB 400 is usually measured with rockwell. Although, perhaps the Rockwell method was not applied then
  5. Mountain shooter
    Mountain shooter 9 September 2020 18: 19
    The Germans, as usual, were extremely rational, in conditions of a global shortage of resources ... Well, the results were ... The Germans always had excellent metallurgists ... there were not enough resources ...
    1. Alexey RA
      Alexey RA 9 September 2020 18: 35
      Quote: Mountain Shooter
      The Germans, as usual, were extremely rational, in the face of a global shortage of resources ...

      In the first year of the war, the global deficit is not about the Germans. A pr country in which the cores of experienced sub-caliber projectiles are made from high-carbon tool steel with vanadium additive, after which the projectile crumbles into tiny pieces when hitting armor.
      And why?
      1) we do not have tungsten reserves and therefore, even if favorable results are obtained, such shells will not have further practical introduction into production;
      2) the manufacture of such cores can only be carried out on grinding wheels, i.e. on equipment that is available in a few factories.

      To produce just one core for a 76 mm projectile requires such an amount of alloy that will deprive at the same time 30 aircraft industry machines it will be victorious for the entire service life of these cutters!
      © Director of NII-24 Averchenko. Chief designer of NII-24 Matyushkin.
      Thanks for the document. Andrey Ulanov.
  6. lucul
    lucul 9 September 2020 19: 43
    It is written so thoroughly ...
  7. zwlad
    zwlad 9 September 2020 21: 15
    We are waiting for the continuation.
  8. Saxahorse
    Saxahorse 9 September 2020 21: 17
    Quite curious. Good materials were selected. Thanks to the author!

    If we talk about saving the Germans already in the first years of the war, then it is worth mentioning the leading belts of shells, which were made of steel, although the technology required copper.

    And here is a controversial point. Is it only for economy of iron? Or were there such charges that the copper belts tore off?
    1. alien308
      alien308 10 September 2020 17: 57
      PTA does not live long. Why barrel durability?
  9. Radikal
    Radikal 12 September 2020 00: 42
    All this is curious, but from the figures for the article it is in no way clear that they are from someone's report, especially from 1942. sad
  10. Andrey Shmelev
    Andrey Shmelev 12 September 2020 22: 12
    Why write such a post - is it not better to post a report? there will be a hundred and five hundred times more huskies
  11. Kerzhak
    Kerzhak 13 September 2020 16: 14
    Very interesting.