Wednesday, 23 November 2022

100 mm D-10 vs 88 mm KwK 43

The Red Army took the threat of German anti-tank weapons very seriously, and the 88 mm Pak 43 remained a reference point for enemy anti-tank guns even after the war. In part, protection from this gun was listed as a requirement for post-war medium and heavy tanks. These requirements allowed me to compare the penetration of the German 88 mm Pak 43 and Soviet D-25T. Turns out, a similar analysis was done using the 100 mm D-10T gun.


This data shows PTP limit (the velocity at which the rear of the plate remains intact) curves of the 88 mm gun against medium hardness cast armour. It is visualized in two ways. The first has impact angle as the X axis and impact velocity as the Y axis. A curve is drawn for different armour thicknesses. The second graph shows the same data, but with the thickness as the X axis and curves drawn for each impact angle.

From these graphs, we see that the 88 mm Pak 43 is a powerful weapon indeed. At point blank range, it can penetrate 120 mm of armour sloped at 60 degrees (incidentally, the armour thickness proposed for modernized IS-2 tanks in 1944). The IS-4's armour protection (140 mm at 60 degrees frontally, 160 mm at 30 degrees on the sides) also offers good but not perfect protection against damage from the 88 mm Pak 43.

At 1000 meters and a velocity of about 900 m/s, the gun can still penetrate 100 mm at 60 degrees or 130 mm at 50 degrees. These look very similar to requirements for the T-54's armour, making it very clear what opponent this tank was designed to fight. 


This data shows the same thing but for the 100 mm blunt nosed AP shell. The penetration is considerably higher. Rather than 120 mm at 60 degrees, the gun penetrates a hair over 160. At 50 degrees, this shell penetrates 180 mm of armour compared to the 88's 150. Unfortunately the graph for the Pak 43 does not show penetration at 30 degrees at point blank range, but extrapolation shows that it penetrated less than 200 mm of armour while the D-10 would penetrate slightly more.

At 1000 meters and a velocity of about 800 m/s the gun penetrates 140 mm of armour at 60 degrees and almost 160 mm at 50 degrees, again keeping a slight edge on the 88. At 30 degrees the gun penetrates 180 mm of armour, making it capable of penetrating both the front turret or the front hull of a Tiger II at ranges where the Tiger II can penetrated it back.



And finally, the 100 mm sharp-tipped AP shell. This shell is not as good as the blunt-tipped AP (same thing is observed with the 122 mm D-25's ammunition as well). At point blank range the gun penetrates 130 mm of armour at 60 degrees, a hair more than the 88 mm Pak 43. At 1000 meters penetration drops to almost 120 mm at 60 degrees or 140 at 50 degrees, still keeping just ahead of the Pak 43. At 30 degrees the gun penetrates less than 180 mm of armour, making it a little riskier to fight a King Tiger head on. 

When it comes to the Panther, a more realistic opponent, the 100 mm gun can defeat it at a great range. The upper front plate (85 mm at 55 degrees) can be penetrated at a velocity of about 600 m/s with the sharp tipped shell (a range of over 3 kilometers) and at even greater ranges by the blunt tipped shell.

RGAE F.8734 Op.8 D.249 L.1-6 via Yevgeniy Narimanov and Artem Belyakov.

4 comments:

  1. It would have been nice to have the distance in meters as an extra Y axis on the right-hand side of the graph. Also, I'm seeing "perfect protection" for the IS-4's frontal hull (140 mm at 60 degrees); the curve goes to point-blank at 55 degrees, unless I'm mis-reading the curve.

    What is PTP? Is it the analogy to the 20 % chance of penetration (with penetration being still defined as 75 % of the shell mass going through)? Or is it something more akin to the British definition of "there's a hole in the armor that light can pass through"?

    How does the data on the D-10 be reconciled with the data done on actual Panther hulls, which concluded that 1400 meters, not 3000, was the limit of the (at least the sharp-tipped) APHE round?

    It would be nice to see the same curves for the D-25T.

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    1. You are reading it correctly, the IS-4 was designed specifically to fight the Ferdinand so it makes sense.

      Yes, it's similar to the British criterion, PTP means there's no spalling, through cracks, etc. seen on the back of the plate. The tests against Panthers were done with early ammo, and after one of the conclusions was that better ammo must be developed to surpass the D-25 in penetration.

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  2. Very interesting. Note that in Yugoslav tests 88mm was not able to penetrate T-54 front armour (100mm@60°).

    I was wondering if it would be possible to translate the graphs' titles and put them in the charts or below as a caption. There are quite a bit of data in this post and it would make life easier. Regards.

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    1. I'd suspect some of the discrepancy between Peter's data above and the Yugoslav T-54 test result would be due to the difference in the definition of 'penetration'. With PTP, (by Peter's comment above; dimpling and cracks may be apparent but there is no spalling) this means that "the armor is NOT penetrated and there have been no significant after-armor effects but the armor but has been significantly compromised".

      With the Yugoslav tests, someone would have had to go inside the T-54 (assuming an actual tank was used) or examine the armor plate (if that was used) and evaluate the back of the point of impact to check if the PTP criteria had been met.

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