Tuesday 20 January 2015

D-25 Reload Angles

For some reason, many people are certain that the IS-2 had to set its gun to a specific angle in order to reload. Over the years, I've heard mostly that it had to be at zero degrees, although some people insist that it had to be fully elevated, or the opposite, fully depressed. The document describing a one piece shell for the D-25 explicitly states that it could be loaded at a great range of angles, and this is using a heavier, less convenient shell. In order to fully dispel the myth, I will provide the loading and firing procedures from the IS-2 manual. This is an early manual (so early that most of it is about the IS-1, errata for the IS-2 is only provided in the very last chapter), describing the screw-breech D-25.

"2. Loading, Aiming, and Firing

The D-25 gun has a separate charge, so it is important to ensure complete ramming of the shell. In order to load the gun, do the following:
  1. Disable the inertial guard in case a shot has not been fired.
  2. Press the breech lever to disengage the breech lock from the loop on the frame.
  3. Move the lever back and to the right as far as it will go.
  4. Place the shell on the tray, disengage the tray lock, and move the tray to the cradle.
  5. Push the shell from the tray onto the guide and use the punch to ram the shell into the breech such that the driving band engages with the barrel rifling.
  6. Insert a propellant charge into the chamber.
  7. Close the breech and place the safety into the "fire" position."
As you can see, no requirement for a specific angle is given. 


  1. Great job Peter Samsonov an another myth about IS 2 (or D25) is busted.

  2. I think the IS-2 is so good that people just make myths against the IS or hard hitting Russian tanks in general.

    1. I don't think it has anything to do with the IS being good or not. Remember that for decades, there was no way to obtain information about the Eastern Front aside from hearsay and German memoirs. The recently declassified Soviet documents are still largely locked inside Russian language books, which will take a while to be translated into English, if they ever will be. A lot of these myths are based on decades-old misconceptions that were carried forward due to a lack of any information on the topic.

    2. I see. But have you gotten any sources (other than hearsay) that state of the supposedly inaccuracy of the D-25 gun?

    3. Practical trials, tactical guides, and firing tables all indicate that the D-25 had no problem engaging targets up to 2000 meters away and even beyond that.

  3. One piece round......Its not relevant as it a later development one round.
    IS85/122 document only speaks about actually loading the weapon I don't see anything that "dispels the myth" as you put it that the weapon needed to be lowered to reload.
    Since you took the stance that this was a "myth" the burden of proof is on you to disprove the "myth" with facts not speculation, lack of evidence in your document is not evidence. Where explicitly does it say you can load the D-25T (WWII types not prototypes) at any angle? Nowhere
    So why do people insist that you needed to lower the weapon to reload? This isn't some random idea similar two part ammunition weapons of the time required it, I believe at least 1 post war SPG had a winch to aid in reloading and still required normalizing the weapon which I do not believe the D25 T on the IS-122 had at least the non-prototype war types.

    1. Manuals tend to describe how a mechanism is operated, not how it is not. If you had to set it at a certain angle, it would be in the manual. Since it wasn't necessary, it's not in the manual. It also doesn't say you don't need to chant a hymn praising comrade Stalin, and yet I don't see anyone claiming that it had to be done.

      It's also funny how you want evidence from me, but not those that perpetuate the original myth. In Russia we called this "please bring me a document stating that you are not a camel".

    2. "Manuals tend to describe how a mechanism is operated"

      Yes, exactly and some focus exclusivity with the mechanical operations only, which may or may not be the case here there is no definitive way to tell ( that my point). In addition to that manuals also often omit and or add considerations in different additions.
      "Since it wasn't necessary, it's not in the manual."
      and how do you know this? You don't you are speculating.... hence you did not dispel a myth you may actually be propagating one.

      "you want evidence from me"
      That's how people remove myth from fact.... you can not claim this is a myth then shrink away when someone asks for compelling evidence, you have made a definitive unequivocal statement (x thing is a myth) with no equally unevilcal evidence on a site dedicated to WWII history. You are supposed to expect question and be able to back up your claims when you make them within the document or else this blog and you are not interested in history but rather dogma.

      Painting yourself as some sort of persecuted victim because I am not demanding people who disagree with you for sources is, pardon my lack of "sayings" misdirection these intangible groups of people who disagree with you are not relevant to this discussion nor are their alleged ( blanket statement btw which is not fair to people who disagree with you) conduct because this is about you calling gun normalization a myth with no sources that back this up not a trial for which group of people is more guilty of not citing sources.

    3. You're pretty mad about someone translating a portion of a manual, man.

    4. It was not my intent to "appear angry" and for that I am sorry (it is my failing) however I may appear is irrelevant the point stands you have not posted anything definitive about wither the 122mm D25T when mounted in a war issue IS-2 needed to level after reloading.

      So far we have:
      1.Anecdotal eyewitness account from 1944 (eye witness testimony is very rarely accurate) I've not been able to track down who gave the testimony definitively but I know who is implied or credited for it.

      2.Speculative reasoning based on gun mechanics and similar weapons ( hardly definitive, incredibly speculative)

      3. A translated document about reloading that doesn't mention anything other than the mechanics of reloading
      By itself its a solid reloading reference for the 122mm D25T, except the speculative conclusion you have come to as there is not even any hint on the document of the conclusion you reached.

      So do you have anything else ( as in evidence not opinion) to add to defend your position?
      If not then the case is unsettled and I suggest if you were serious and respectful about history you'd rewrite the article and strip off your conclusions.

    5. Click the link in the third sentence of the article. It explicitly gives the range of reload angles for a one-piece round. Why would that have a range of angles, while the lighter and smaller pieces of a two-piece round have to be loaded at a specific angle?

    6. Anonymous, I must wonder how the fact that in the procedures the need to flatten the gun is NOT mentioned is not strong, even definitive evidence they don't need to flatten the gun.

      Especially since as you tacitly admit, the cards on your side (anecdotal eyewitness account) and speculative reasoning are pretty weak.

      It seems that you are demanding an impossibly high standard to prove that they DON'T need to flatten the gun, while weak evidence and speculation is sufficient for the other side.

    7. @ Peter
      Nothing new same speculation which I already wrote at length about. Please remove your unsupported conclusion/comments or at least reword so that it is clearly marked as your opinions and not fact.

      @Ark My side? Where might I ask did I ever show support to any side?

      I listed everything I've personally seen on the IS-2 and Peter's conclusion which is no better than those other highly speculative ideas floating around the internet,books, other media. I make no claims that the IS-2 needed to do anything at all. I also gave some background because of the author's remarks about gun leveling in the article.

      The point of my posts is to highlight the lack of evidence used to claim that gun leveling was a "myth" all we currently have is the author jumping to a conclusion based on speculation that is not even hinted at in the IS-2 article!?

      As shown there is nothing so far I've come across (including this article) that proves gun leveling one way or the other (true or false).

      As far as having Impossible standards? really?
      I ask what anyone should of someone making such an unequivocal statement Actual evidence rather than speculation. When has evidence been too high of a standard? Perhaps when the evidence is not there?

    8. You still haven't explained why a smaller and lighter object would be harder to load than a big and heavy one.

    9. The day you read an article claiming to refute a claim and comment against that assertion you have taken a side.

      I won't call even the guys who started this 'jumping' really, if they really had an anecdote to hand, in the absence of anything more concluding the gun needs an angle to load is reasonable. Even a hypothesis based on characteristics of other guns is OK as an initial stab.

      However, in the face of a manual, which you tacitly admit is superior evidence, to insist there is reasonable doubt seems to be favoring the other side a bit much. Yes, with a manual lack of evidence is evidence of lack.

      Maybe if there are HUNDREDS of testimonials concerning the need to angle the gun, and they all claim the same angle, then there is room for discussion. Sometimes manuals do prove to be impractical in real life. But that does not seem to be the case.

      I'll also suggest if we really have anecdotes of the guns having to be loaded at maximum, flat and minimum angles, that an inclusive interpretation will say the gun can be loaded at all angles, and people are recalling their personal or maybe regimental twist.

      So where is the doubt?

    10. the doubt is that the article does noting to disprove the so-called myth .It takes a document and states well this documents does not mention anything about X thing so X thing is a myth. Right so if someone does not label blech to be toxic then its safe to drink? no its disingenuous to jump to a conclusion because said thing is missing in 1 document. How about talking to IS-2 crew and asking them about reloading the weapon in a WWII era IS-2 during combat or finding reinactors load a real accurate WWII era IS-2? Instead we are stuck on assumptions not fact.

    11. I don't know why you're assuming that the myth is true without any evidence and then assume that the manual for the gun would be lacking this allegedly specific instruction. You are welcome to peruse iremember for IS-2 loaders that remember lowering their gun to reload. I didn't find any.

    12. I am not I am stating support for anything. I only state that you did not disprove "the myth" as you put it as all you did is provide an opinion and no facts to back up your claim.

    13. I didn't know that the manual for the D-25T and testing data on the one-piece round were just based on my opinion. I didn't know that I was such an influential thinker in 1944.

  4. I'd put more faith in Google Translate™ rather than this mess with the middle man commentary.....

  5. The manual did not specifically support your claim therefore your claim that the IS-2 did not need to 0 to fire is an opinion as is your assertion that you "busted a myth".

    1. My point is that there is no evidence for a zero degree reload angle in the manual or any associated documentation. What's more, there is explicit reference to multiple reloading angles being possible, whereas the zero angle reload crowd has yet to come up with even a single document supporting their claim.