Sunday, 28 July 2013

Ballistic Tables of the 8.8 cm L/71 KwK 43

I have written previously on the precision of various tank guns, and the "long 88" 88L/71 KwK 43 showed up in those comparisons. Sadly, the only data I had was the percentage chance to hit a target of a certain size, which, while allowing for a crude comparison, didn't give me the numbers I needed. However, thanks to some enterprising folks at Tank-Net, I have a ballistics table for the gun! From H.Dv.119/329 - Vorläufige Schußtafel für die 8,8 cm Kw.K. 43 u. 8,8 cm Pak 43 (Sept. 44), pp. 104-107:


How convenient, the precision figures are also for 50% dispersion, which makes it nice and easy to compare them with the Soviet ones without doing any math. Columns 5, 6, and 7 are for depth, width, and height, respectively. Units are in meters.

The dispersion at 1000 meters is pretty small: 30 cm in width and 50 cm in height. However, let's compare that to some values from the previous article:

  • F-34: 30 cm by 30 cm
  • M2: 30 cm by 30 cm
  • sFH18 105: 20 cm by 40 cm
  • ML-20S: 33 cm by 22 cm
Not very impressive anymore, is it? The allegedly superior precision of the very long 88 mm gun pales in comparison with guns on tanks some consider inferior (T-34 and M3 Lee) and short barreled howitzers, which are also typically considered imprecise. 

22 comments:

  1. While not impressive compared to other guns, the fact that any of them are that accurate is pretty neat. Certainly wouldn't have expected it out of the shorter guns, in particular.

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  2. Very interesting. Any figures for ranges beyond 1000 meters? I would suspect that the long 88 might fair a bit better at 2000 meters compared to some of these other guns. I also suspect that some of the 88's reputation for accuracy has to do with it's muzzle velocity and flat trajectory. So while it my not technically be more accurate at 1000 meters than the 75mm M2, it's probably easier to aim since the flatter trajectory of the round means the gunner has to do less adjusting for range. Of course, that's just an off the top of my head theory. While I certainly think that German equipment is often overrated compared to Allied kit, there must be some basis for the 88's reputation for accuracy.

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    1. The 88L/71 table goes up to 4000 meters. The 75 mm M2 table sadly only goes up to 3000 meters. At that range, the deviation of the 88L/71 is 1 meter by 1.4 meters, and the deviation of the M2 is 2.3 by 0.9 meters. So yes, it's more accurate at such an extreme range. However, at that range, the F-34's deviation is 1.1 meters by 1.0 meters. It's still more accurate. Plus, engagement at those ranges is very, very rare.

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  3. Speaking of doing some math. The German data is for a rectangle about the aim point. Thus it is like a diameter. The Russian data is a radius from the aim point.

    The F-34 50% dispersion would be equivalent of .60m by .60m in German terms.
    The German formula would calculate its chance to hit at 3000m:~35.5%

    Thus ends the lesson.

    PS, Thanks for the excellent research.

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    1. I don't know where you went to school, but "rectangle" and "diameter" are not two words that I commonly associate with each other.

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    2. First, in no way you answered the issue that in data quoted by you the dispersion is measured differently.
      Second, the diameter of a set is very well defined in college level math. It is a maximum distance over all pointpairs belonging to the set. So a rectangle has a diameter.
      Lastly, someone came and raised an issue with your data/conclusions. The first thing you did was to suggest them illiterate (where you went to school).

      In short - historical revisionism applied.

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    3. The dispersion is not a diameter, it is a radius. It is calculated as an absolute value from the center of where the gun is aiming. In this case, measuring the diameter results in exactly zero useful information for the gunner.

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  4. A circle drawn over a square rectangle with a radius = 1/2 the square's width will have the diameter = width.

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  5. The German tables do NOT take into account range estimation. They are measures of shot dispersion, and do NOT take into account trajectory flatness. The flatter the trajectory, the easier it is to hit a target at range. Shot dispersion is only one factor in determining battlefield accuracy. It is important but it is not the whole story. -- posted by R. Livingston

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  6. This seems like a desperately weak attempt to discredit the 88
    A deviation of around 1m at 3000m is not enough to prevent a round on a tank-sized target. The flat trajectory means less reliance on exact range estimation, and German doctrine was to open fire at 1500m. I get there is a strong pro-soviet bias to this blog, but you are just offending the bravery of the troops who had to go up against this weapon, knowing it could kill that at long range while their own weapons are effectively blind or useless

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    1. I'm not saying that the KwK 43 can't hit at 3000 meters, I'm saying that, given accurate range estimation, every gun that I have data for can hit at that range. Accurate range estimation is the key here, since it was extremely hard to do with WWII era technology. If you look at actual data, the vast majority of tank on tank engagements took place at a range of only a few hundred meters, not 1.5 km.

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  7. The basic mistake resides in the inability of the author to understand the difference in defintions. The german sources give 50% dispersion as a constructive rectangle centered on the MPI.

    The soviet 50% dispersion is given as a RADIUS, for both height and width.

    Since the radius is only 50% of a diameter and the diameter is similar to the width and height, respectively of the rectangle when measuring from edge to edge over the centre, You have to MULTIPLY the soviet figures by 2.0 or DIVIDE the german figures by 2.0 in order to obtain the same measurement scale level.

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    1. Then how come when you compare these figures to the Soviet trials of the KwK 43 they match the radius?

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  8. Do they? I rather see an insufficient sample size to arrive with such a conclusion.

    That being said, I have the gunnery instruction pamphlet right in front of me, and it explains these zones of 50% hitting confidence.
    The germans -unlike the soviets- do not use the radius in this context.

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  9. Well, it would need transcription and translation to be of any worth and I lack time to complete the document. However, it explains how the figures were arrived. Including details of shot numbers per cal required, calculation of the mean point of impact, identification of outliers, calculation of mean dispersion 50% in x,y and z, probable error and hitting probabilities depending on distance and target geometry.

    it doesn´t seem to me that soviet and german figures can be easily compared because both used different methods to obtain their results and it doesn´t follow that this can be corrected for with a fudge factor. A marked difference in establishing the firing tables, f.e. is that the soviets do not compensate for a shift of the mean point of impact in a pattern caused by dayly influence (presuming MPI = centre in order to allow for drawing radii), while the germans first determine the MPI from a series of shots and then subsequently determine the pattern size after MPI compensation. They use different ´shot sample sizes, too.


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    1. You seem to have plenty of time to weave fantastical tales in my comments, surely you can spare a minute to scan such a valuable document.

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  10. Exactly those comments do encourage me not to invest my time to help You understand but rather to refute Your impressive tale stories embedded in this blog...

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    1. So we're back to the same point we're always at with you: everyone else is wrong and you're right, based on information that only you possess and are unwilling to share. But we should trust that you're right, just because.

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  11. Well, You are free to go to BAMA and look it up Yourselfe. The document is called "Leitfaden für den Artillerieunterricht" Vol. I, Ballistik form the issue 1939 (Berlin), issued and edited by the Artillerieinspektion. If You have it located, Chapter XI. "Trefffähigkeit und Streuung" as well as Chapter XII. "Einrichtungen und Gebrauch von Schußtafeln" deals with the problem. About 12 pages worth to read with examples.

    The principle to define 50% probability rectangles was the same for all services: Army, Navy and Air forces, and predates 1906.

    The oldest, but quite detailed description of this system I have seen on this topic is in the 1906 edition of the Leitfaden für den Artillerieunterricht -I believe it was the navy edition in this case but an Army edition is aviable in BAMA from 1908, and I do not claim that these are necessarely the oldest descriptions of the system.

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  12. Ahh, You don´t even need to go to an archive, as You will find plenty of references sourcing online libraries such as archive.org
    as the system was not a secret to anyone and also employed virtually unchanged, f.e. by the USN.

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