Tank Guns and Ammunition

Discussion in 'Land Forces' started by Kunal Biswas, Jul 21, 2012.

  1. Akim

    Akim Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..


    3BM-42 go widely to the export with Т-90, BM Oplot. 3ВМ44М, put is AL in Т-72Б2 and in Т- 90 with a reducer. 3BM44U1 is put in ML of BM Bulat and BM Oplot without problems.
     
  2. Akim

    Akim Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..

    You are right, a bit will remedy an error.
    3BM44М and 3BM44U1, comparable with rounds DM43A3.
     
  3. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    I now assume that there is some standart when measuring potential energy (since official sources give figures I posted initially) while this does not reflect specific figures of different rounds, it is valid for relative comparison of potential of gun.

    Well, I do not think examples of RH 120 are valid as it is another generation.

    Indeed, 2A82 has higher chamber dimensions (gun is unified with 152mm 2A83) allowing bigger quantity of propellant to achieve much higher performance. It approaches in performance to 140mm rather than 120mm. In fact, for it there are developed new projectiles which are not compatible with previous guns.

    Comparison with RH L/55 is not valid as it is another league, also to note, current rounds (DM-53/63) do not aproximate 2000m/s.


    Pressure limit is equivalent on both.

    Again, I do not see the point in comparing projectiles (I am specifically talking about gun performance), less if you compare old munition (?).

    Facts are :
    - RH L/44 caliber 120mm lenght 5.3m
    - 2A46-M caliber 125mm lenght 6m
    - RH L/55 caliber 120mm lenght 6.6mm

    So there you have relative performance (note, 2A82 is not valid for such comparison).
     
  4. Damian

    Damian Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..

    2A82 and 2A83 are bicalliber weapons? Just like XM291? With a common breach block and replacebale 120mm and 140mm barrel (in case of 2A82/2A83 with replaceable 125mm and 152mm barrel)?
     
  5. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Yes, 2A82 and 2A83 have some common (unified) components. When I find patents I'll show in more detail.
     
  6. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Is that so? How comes that small tanks like Obj. 780 and 785 could carry even more 125 mm rounds for the 2A82 tank gun than the T-80 and T-90 can carry, when the ammunition for the 2A82 is bigger? If you can provide a source, then I may believe you. But currently there are some facts speaking against the 2A82 having a larger chamber than the 2A46M-x tank guns.

    Sure they do not reach 2,000 m/s, because that is dumb as shit. Muzzle velocity is one factor relevant for penetration and it does not affect penetration linearily. It makes more sense to accelerate a larger mass at a lower velocity, because this will offer more armour penetration (depending on velocity and mass).
    It is however possible, given the known performance of the Rh 120 L/55 and the current generation powder to accelerate a 6 kg projectile at 2,000 m/s - this wouldn't make any sense, but it is possible and lies in the limits of physics. You can also accelerate a smaller projectile (something in the area of 3-4 kg) to 2,000 m/s if you would like to... but this will not offer reasonable performance against enemy armour.

    It is not. Rh 120 L/44 has a limit of 7,100 bar, Rh 120 L/55 has 500 bar more limit, while the 2A46M-x series have a pressure limit of only 6,500 bar (or kgf/cm² according to KMDB - Kharkiv Morozov Machine Building Design Bureau, which is actually below 6,500 bar).

    Length is not the sole determining factor when it comes to performance. The 2A46M tank guns cannot support as much pressure as the Rh 120 series and therefore perform slightly worse, even though being longer.
     
  7. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Those projects do not reflect T-80 and T-90n as their dimensions were increased and they had different configuration (780 in fact carried less, and 785 was heavier, had different gun and difference was not very significant despite).

    Also to note that designation may refer to different guns (today's 2A82 being further developed). Same as for example soviet Svinets rount has nothing to do with today's Svinets-1 and Svinets-2.

    T-90 is also compatible with 2A82 but requires modifications.

    2A82 is about achieving higher performance due to allowance of more propellant, and sustaining much higher pressure. Now all what we have are patents, but all points that projectiles for it are not compatible with 2A46-M series, so it is significant difference.

    This may be valid for currently used ammunition and guns. In USSR (now Russia) 2A82 and 2A83 represented two different approaches to increase penetration, first is increase in velocity, second more significatnt, adoption of larger 152mm caliber (also objective was to achieve very high velocities). In US also objective of future gun, was to achieve energy of 20MJ and velocities of 2000m/s, so again, examples for RH 120 do not serve for comparison as it is different league.

    Figures for RH 120mm and 2A46-M cannot be used for direct comparison as they have different dimensions, Pressure figures are given for specific gun, but not in same context with the other.

    But we have a more valid comparison. In Russia there were developed two 120mm guns, M-393 and M-395 designed for export, fully compatible with NATO ammunition.

    M-393 for T-62 has same dimensions (5.3m lenght as RH L/44) and it is said to be analogue in characteristics. M-395 for T-72 is equivalent to 125mm 2A46-M and it is said to be higher in performance than RH L/44 but not than L/55, so this comparison corresponds to 125mm 2A46-M.
     
  8. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Yes and the same way we cannot compare barrel length without into account that they have different calibers and operate at different pressures. What we can however see are the results: That the Rh 120 L/44 can achieve an energy output above 11 MJ, while the last actually known 125 mm rounds had a maximal energy output of 10.18 MJ. So the Rh 120 L/44 is the better gun system based on what we actually know. It might be that Svinets-1 and Svinets-2 can achieve a similar energy output, but I have never seen any source about them. I have asked members of Russian forums if they have some information about these latest Russian rounds or if they know wether they have entered service - but noone knew a single thing. Maybe Svinets-1 and Svinets-2 are operating at a higher pressure (even though I doubt this given the limitations of the 2A46M-x series) to reach a higher energy output, but it is also possible that they stayed at the same energy level and have only a redesigned layout. There are no sources indicating that this ammunition has entered service and that it is superior (in terms of muzzle energy) than it's predecessors.

    You are aware that muzzle energy and muzzle velocity are different things? To reach 20 MJ with a muzzle velocity of 2,000 m/s you would need not less than 10 kg projectile. Try to fit a 10 kg KE projectile into the T-90A autoloader or any other currently used... it does not fit. A 10 kg APFSDS round would even exceed the limits of the latest T-90A autoloader. All previous Russian/Soviet rounds of which the dimension are known weighed less than 8 kg.

    I think you should see why I have to doubt your words.

    Who said that? Noone I have ever seen and not a single article/book I have read ever claimed that the 2A46M-x outperforms the Rh 120 L/44. Actually the contrary has been claimed various times.
     
  9. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    I said, comparison of munition does not reflect gun performance (more so, your rounds are not modern and are under gun potential).

    Limitations of 2A46-M series, that has not any base. You focus on figures on pressure without understanding that they cannot be used for direct comparison. Figure for 2A46 is specific having in account it's dimensions, chamber (more volume) than RH 120. If you want to see they are comparable, you can do your calculation, I is already known howewer already know that both are comparable.


    I am perfectly aware. I also know that these figures are for another context in different gun, so what you say about current 120 mm projectiles is not valid. Besides, I only repeated figures given by official sources. I did not calculate anything as I think it is not worth given again different context and lack of information...

    Russian rounds as you know consist of two parts, propellant and so called active part which holds proper projectile. Comparison of 2A46-M rounds for 2A82 is not valid, rounds developed for it require a significantly bigger propellant part and very likely, different subcalibre rounds to achieve higher penetration. It is therefore not compatible with 2A46 and comparison is not valid again.


    Modernised 2A46-M is comparable and that is objective logic, besides it is well known in Russia.

    There is a technical article on guns: 120-ìì ïóøêà äëÿ òàíêà áóäóùåãî MCS

    Interesting part, translated:
    So there is valid comparison, with 2A46-M
     
  10. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Oh, you can tell me what I understand and what I do not understand? Interesting...
    Let me tell you something: You can continue to tell me that I do not understand or know something, but I do understand this in fact and it does not help you in any form in this argument. Facts and sources help, not just saying "you don't understand". The latest "high power" APFSDS produced in the Soviet Union have a maximum chamber pressure of more than 540 MPa at 15°C. This is comparable to some NATO APFSDS used in this time - however the pressure limit of the 2A46M-x series of tank guns is lower and all types of conventional propellants are affected by temperature. That the chamber of the 2A46M-x tank guns are larger than the NATO chambers (according to you, not really in reality) does not affect the fact that the temperature does affect the pressure to the same degree it does affect the pressure in the NATO chambers. The lower pressure limit will result in less powerfull propellant. If the figures from Kharkiv Morozov Machine Building are correct, then firing the 3BM-42 Mango at temperatures above 40 to 50°C will exceed the maximum chamber pressure and disable the gun. This fact is supported by mathematics based on the laws of physic and by official values from ROSOBORONEXPORT.
    Using late Soviet APFSDS (3BM-42, 3BM-46) would essentially destroy the earlier 2A46-1 and 2A46-2 tank guns even at 15°C!

    Then again the 2A46M-x series does not have a greater chamber volume... 120 mm NATO has a maximum chamber diameter of 150 mm and a length of 570 mm, while the maximum diameter of the Soviet 125 mm ammunition propellant charge is 129 mm for the projectile and aprox. 150 mm for the extra charge. the 125 mm ammunition is longer, but the part which has a diameter of 150 mm is shorter. Propellant weight is nearly the same, so is volume.

    What now? Do you want to claim that the Soviets managed to produce insensitive propellants decades prior the NATO?

    And where can I find these official sources?

    It is not objective logic. First of all you claimed that the 2A46M-x tank guns are better than the Rh 120 L/44... and even a blind person will see that this is complete *****.
    Then the second point is that 2A46M-x series of tank guns can use the latest rounds only to temperatures of maximum 50°C because else the maximum pressure will be exceeded, while the Rh 120 L/44 can use higher pressure munition at temperatures higher than 60°C... but you want to tell me that this does not make the 2A46M-x series of tank guns inferior to the NATO competitors?

    Sure, a Russian article about a Russian gun is definetly impartial. I have seen German and English-language sources claiming that the Rh 120 L/44 is better in terms of performance. I don't know the Russian author there, maybe he is trying to be impartial, but on the other hand he could also be a propagandist.
     
  11. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    I am not interested in amateur analysis of advertising material, and not in ammunition. Here I am discussing potential of different guns. New rounds are being developed, approaching maximum limits and gun will dictate it's performance.

    I do not understand how person can take specific figures for specific gun out of context and make plain comparison with another gun.

    In 2A46-M characteristics are different, chamber, and bore diameter. So if you adjust figures you provided, you get pressure equivalent to RH 120mm. For example, with two guns, 120mm and 125mm of same lenght, 6.500 bar in 125mm results in higher performance than 6.500 bar in 120mm. In fact RH 120mm needs to have higher pressure to match 125mm (was it difficult to realise ?). Your comparison method was just wrong.

    So adjusted figures for 125mm are more or less equivalent, being the gun longer it achieves more potential energy.


    For what in specific ?

    Your amateur analysis advertisement material of old rounds is not valid to measure gun potential (how many times I have to repeat).

    New rounds are being deployed, so my interest in gun potential as it is what will make important difference.

    You should stop with this inmature attitude. This is valid technical material I provided.

    And I do not understand inmature BS you spread about guns.

    1980s modernised 2A46-M should be worse than NATO gun of same period ?? For 125mm caliber and 6m lenght gun to be worse, it would need to have a much lower pressure, this is against all sense.

    Sorry, but I cannot believe such bullshit (especially without facts), about why Soviet gun should have much lower pressure than Western gun of same period. And facts show the opposite.
     
  12. Damian

    Damian Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..

    WTF is this?

    Methos provided calculations and where to find data about specific guns, and here with have a Bellarusian from Moscow, that calls him imature, and in the same time not providing any sources, calls even official Russian sources "advertisement material" only it disproves it's own fantasy.

    Hey, I was not wrong afterall, You seems to be the same kind of propagandists as Khlopotov and Tarasenko are. :pound:

    Of course You can't belive in anything that stands against official state propaganda, do You? ;)

    And why west could not achieve better results? Especially if they had different approach to solving the same problem than the Soviet Union.

    I find it amusing that people from ex Soviet block like You, are completely unable to comprehend a simple fact, that to solve the same problem, someone can find a different solution, that in the end might be better. For example metallurgy.

    There are many more examples.
     
    Last edited: Aug 19, 2012
  13. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Fact is that Methos provided no calculations at all. He took data related specifically to gun, and compared it with another without adjusting.

    And here we do not value amateur calculations, but official figures and technical information.

    Damian, I see you do not understand this subject, so I will not be repeating myself for you.
     
  14. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    You are the one posting bullshit here. I do not think we need to continue this discussion. You are not interessted in providing any sources and you do not ask for any. How old are you? Grow up!
     
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  15. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Ok, so we are back to the point.

    So let's start again.

    What defines potential of gun, pressure, bore diameter, lenght.

    We know:
    2A46-M is 6m loong compared to 5.3m RH L/44 and 6.6m L/55.
    125mm compared to 120mm

    Max pressure is not exactly known. On Ukrainian gun it is given as about 6.500 bar but having in account it is different gun and bore lenght, it will approach 7000 bar of RH 120 mm. So there is no significant difference.
     
    Last edited: Aug 19, 2012
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  16. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    So, know you even try to change facts?
     
  17. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    What I changed ? I properly used available figure, or do I need to explain it again ?
     
  18. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    On what you originally support your claim about lower max pressure of Soviet guns:

    - Pressure limit is equivalent on both.
    - It is not. Rh 120 L/44 has a limit of 7,100 bar, Rh 120 L/55 has 500 bar more limit, while the 2A46M-x series have a pressure limit of only 6,500 bar (or kgf/cm² according to KMDB - Kharkiv Morozov Machine Building Design Bureau, which is actually below 6,500 bar).

    Here you commited big mistake. Your logic is, 6.500 < 7100 but this is nosense.

    Gun potential is given by bore diameter, pressure and lenght 6.500 bar in 125mm is higher energy, approaching 7000 if we adjust for 120mm.

    So energy of Soviet and Western gun, without having in account additional lenght of Soviet model, is already comparable.
     
  19. Akim

    Akim Defence Professionals Defence Professionals

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    I a bit will enter into your dispute. Pressure is natural in the channel of barrel at the German guns anymore, she shorter almost by meter. And characteristics are similar. Only forget one. At RH more weight and correspondingly big recoil at a shot. It is not substantial for Leopard, but the tanks of series of "Т" weigh on 10 tons less than. And a similar dispute conducts you to nowhere. Here if argued, about RH120 L/55 and 2А82 and "Vityaz" It is the nearest future. Because, 140-мм long set still will not. . And conclusions about 2А46М and RH 120 L/44 - a long ago already a made.
     
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  20. hest

    hest Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    More arguments:

    Factor defining power of gun, square of the caliber. Under the same conditions (lenght, etc), but differing in caliber, 125mm gun will be about 10% more powerfull than 120mm.

    So even if you have 125mm gun with 5.3m lenght and max pressure of 6.500 bar, it is equivalent to 120mm with 7100 bar and 5.3m.

    It further confirms that 125mm gun with 6m (additional lenght) is significantly more powerfull than RH L/44, approaching L/55.
     

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