Monday 26 June 2017

Soviets vs M48 Patton

Fig. 2 Tactical diagram of complete penetration and satisfactory penetration limits when firing at an M48 tank with domestic 85 mm sharp tipped capped armour piercing shells.
Muzzle velocities higher than stock were tested at 100 meters with an increased charge.
  1. Complete penetration limit of the lower front hull.
  2. Rear plate integrity limit of the lower front hull.
  3. Complete penetration limit of the upper side of the hull.
  4. Rear plate integrity limit of the upper side of the hull.
  5. Complete penetration limit of the lower side of the hull.
  6. Rear plate integrity limit of the lower side of the hull.
On the resistance of the hull to 85 mm sharp tipped capped armour piercing shells, it can be said that:
  1. The upper front hull, 110 mm thick at an angle of 60 degrees, cannot be satisfactorily penetrated with an 85 mm shell fired at 800 m/s at any angle.
  2. The lower front hull, 80 mm thick and an angle of 54 degrees, can be penetrated at 0 degrees at a velocity of 780 m/s, which corresponds to a range of 200 meters. However, a complete penetration of this part of the hull is not guaranteed, and can only be achieved with shells at a muzzle velocity of 820 m/s.
  3. The upper sides of the hull, 80 mm thick at an angle of 45 degrees, can be penetrated at 90 degrees at a velocity of 720 m/s, which corresponds to a range of 850 m. The limit of satisfactory penetrations in these conditions is equal to 680 m/s (1250 m). The range of safe maneuver of this part of the hull is 52 degrees*.
  4. The lower sides of the hull, 80 mm thick at an angle of 30 degrees, can be penetrated at 90 degrees at a velocity of 600 m/s, which corresponds to a range of 2200 m. The limit of safe maneuvering of this part of the hull is 38 degrees.
*) Safe maneuvering angles are calculated from satisfactory penetrations only.

Fig. 3 Tactical diagram of compete penetration limits when firing at an M48 tank with domestic 100 mm armour piercing sharp tipped and blunt tipped capped shells.
Muzzle velocities higher than stock were tested at 100 meters with an increased charge.
  1. Penetration limit of the upper front hull with blunt tipped shells.
  2. Penetration limit of the lower front hull with sharp tipped capped shells.
  3. Penetration limit of the lower front hull with blunt tipped shells.
  4. Penetration limit of the upper sides with sharp tipped capped shells.
  5. Penetration limit of the upper sides with blunt tipped shells.
  6. Penetration limit of the lower sides with sharp tipped capped shells.
  7. Penetration limit of the lower sides with blunt tipped shells.
Fig. 4 Tactical diagram of the satisfactory penetration limits when firing at an M48 tank with domestic 100 mm armour piercing sharp tipped and blunt tipped capped shells.
Muzzle velocities higher than stock were tested at 100 meters with an increased charge.
  1. Satisfactory penetration limit of the upper front hull with sharp tipped capped shells at an angle of 0 degrees.
  2. Satisfactory penetration limit of the upper front hull with blunt tipped shells.
  3. Penetration limit of the lower front hull with blunt tipped shells.
  4. Penetration limit of the lower front hull with blunt tipped shells.
  5. Penetration limit of the upper sides with sharp tipped capped shells.
  6. Penetration limit of the upper sides with blunt tipped shells.
  7. Penetration limit of the lower sides with sharp tipped capped shells.
  8. Penetration limit of the lower sides with blunt tipped shells.

    On the resistance of the hull to 100 mm blunt tipped and 100 mm sharp tipped capped armour piercing shells:
    1. The upper front hull cannot be penetrated with the 100 mm gun with a muzzle velocity of 895 m/s with the specified types of shells at any angle. However, if the muzzle velocity of the 100 mm gun is increased to 1000 m/s, the specified part of the hull could be penetrated by the blunt tipped shell from angles in the +30 to -30 degree range. The sharp tipped capped shell cannot deliver unsatisfactory penetrations to this part of the hull even at this speed.
    2. The lower front hull can be penetrated at an angle of 0 degrees with a blunt tipped shell with a velocity of 660 m/s (range of 2500 m) or a sharp tipped capped shell at a velocity of 750 m/s (1450 m).
      At the stock muzzle velocity (895 m/s), the lower front hull can be penetrated:
      1. With a blunt tipped shell, in the +55 to - 55 degree range.
      2. With a sharp tipped capped shell, in the +38 to -38 degree range.
        The limits of satisfactory penetration at 0 degrees with blunt tipped and sharp tipped capped shells are equal to 610 m/s and 700 m/s respectively.
    3. The upper sides can be penetrated with blunt tipped or sharp tipped capped shells at +/- 90 degrees at velocities of 570 m/s and 625 m/s respectively (3600 and 2950 m). The limits of satisfactory penetration are equal to 535 m/s and 560 m/s. The safe maneuvering angles equal to:
      1. With blunt tipped shells: +/- 25 degrees
      2. With sharp tipped capped shells: +/- 34 degrees
    4. The lower sides can be penetrated with blunt tipped or sharp tipped capped shells at +/- 90 degrees at velocities of 495 m/s and 475 m/s (4500 m and 4800 m). The limits of satisfactory penetration are equal to 470 m/s and 425 m/s. The safe maneuvering angles equal to:
      1. With blunt tipped shells: +/- 19 degrees
      2. With sharp tipped capped shells: +/- 28 degrees

    Fig. 5  Tactical diagram of complete penetration and satisfactory penetration limits when firing at an M48 tank with domestic 122 mm blunt tipped armour piercing shells.
    Muzzle velocities higher than stock were tested at 100 meters with an increased charge.
    1. Penetration limit of the upper front hull.
    2. Satisfactory penetration limit of the upper front hull.
    3. Penetration limit of the lower front hull.
    4. Satisfactory penetration limit of the lower front hull.
    5. Penetration limit of the upper side.
    6. Satisfactory penetration limit of the upper side.
    7. Penetration limit of the lower side.
    8. Satisfactory penetration limit of the lower side.
    On the resistance of the hull to 122 mm blunt tipped armour piercing shells:
    1. The upper front hull cannot be penetrated by 122 mm shells at 781 m/s at any angle. At a velocity of 900 m/s, this part of the hull can be penetrated within +/- 18 degrees.
    2. The lower front hull can be penetrated from an angle of 0 degrees at 590 m/s (2600 meters). The limit of acceptable penetration is 540 m/s (3400 m). At 781 m/s, this part of the hull can be penetrated within +/- 53 degrees.
    3. The upper side can be penetrated at 435 m/s (5300 m). The angle of safe maneuver is +/- 26 degrees.
    4. The lower side can be penetrated at 390 m/s (6100 m). The limit of acceptable penetration is 315 m/s (7400 m). The angle of safe maneuver is +/- 20 degrees.
    Conclusions:
    1. The armour protection of the American M48 medium tank is increased compared to previous designs (M46 and M47). This increase is achieved due to variable armour thickness height and perimeter wise, and due to highly sloped armour of the hull and turret, which was achieved by widespread use of casting.
    2. Domestic 100 mm and 122 mm guns are effective measures against the American M48 tanks. Out of the two types of 100 mm shells (blunt and sharp tipped), the blunt tipped is more effective.
      However, neither the  100 mm blunt tipped shell with a muzzle velocity of 895 m/s nor the 122 mm blunt tipped shell with the muzzle velocity of 781-800 m/s can penetrate the upper front hull of the M48 tank.
      In order to penetrate this part of the hull at 0 degrees, the 100 mm shell must have a velocity of at least 940 m/s, and the 122 mm shell - 870 m/s.
    3. Domestic guns with a caliber of 85 mm or less are ineffective against the armour of the M48 tank. It can be assumed that any part of the hull can be penetrated with 85 mm HEAT shells.
      The resistance of the armour of the American M48 medium tank to HEAT shells is not included in this article. Data regarding the resistance to HEAT shells will be published separately."

    10 comments:

    1. I think that there is a typo in the "resistance to 100mm" section:

      "The sharp tipped capped shell cannot deliver unsatisfactory penetrations to this part of the hull even at this speed."

      Are you sure that the "unsatisfactory" is correct?

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      Replies
      1. Yes, even unsatisfactory penetrations (for example, penetrating in a place that was struck by another shell previously) were not achieved.

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      2. Thanks. I will edit my T-54 article with reference to this new information. BTW, I assume that in the 100mm section, "blunt tipped AP" refers to BR-412B and "sharp tipped capped AP" refers to BR-412D, right?

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      3. The only sharp tipped AP for the D-10 was 53-BR-421 without any letter code, both B and D were blunt AFAIK.

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      4. That's weird. I've never heard of 53-BR-421 at all, and surely BR-412 is considered sharp tipped AP?. And BR-412D isn't blunt except for the cap. It's got a relatively sharp tip beneath its blunt cap: https://4.bp.blogspot.com/-SzTvuwDAdKw/V8G_Rfd8N4I/AAAAAAAAHQA/_mKTqXiEsjYlFbdLx8zQvh47MlLXmI15ACLcB/s1600/br-412d.png.

        But if BR-412D is said to be blunt in documents then there is no point arguing against that, of course.

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      5. BR-412, not 421, sorry. Also in Soviet nomenclature BR-412D is called бронебойный тупоголовый с защитным и баллистическим наконечниками, трассирующий (armour piercing, blunt tipped, with cap and ballistic cap, tracer). BR-412B is бронебойный тупоголовый с баллистическим наконечником, трассирующий (armour piercing, blunt tipped, with ballistic cap, tracer).

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      6. Thanks. There still appears to be an inconsistency in the post, though. Under Fig. 3 sharp tipped shells are mentioned and under Fig. 4 there are references to sharp tipped capped shells. Why would they be testing obsolete BR-412 (sharp tipped), and what could "sharp tipped capped shells" be referring to?

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      7. Who knows, the tendency to describe the shell instead of giving its type is pretty annoying.

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      8. Thanks anyway. I didn't think that "sharp tipped capped shells" could be referring to BR-412D anyway, since it is not likely that BR-412D would perform worse than BR-412B on a high obliquity target like the upper front plate of an M48. After all, it is proven by multiple sources that BR-412D performs better at 30 degrees obliquity than BR-412B, and I doubt that it is any different at 60 degrees.

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    2. The BR-412D will penetrate more 0° and 30° armor since it is a capped AP shell that won't shatter easily against thick armor compared to sharp or blunt nosed AP shells. Sharp nosed AP shells will shatter against sloped armor making them blunt and helping to normalize agains the armor like shells that are already blunt. APC has generally less performance against 60° armor than sharp or blunt nosed AP shells since the cap keeps the nose from shattering. So the APC shell might actually ricochet or fail to penetrate because a lot of its energy is getting deflected from the armor. You can either have good performance against flat armor or sloped armor but not both.

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