Tank Guns and Ammunition

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

  1. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    Cold War Era Russian 152mm M-69 "Taran" (Battering Ram) Gun

    [​IMG]

    This rifled gun was developed by the OKB-9 (now Spetstekhnika) design bureau in Sverdlovsk (now Ekaterinburg) in 1960 and was mounted on an experimental vehicle Ob'ekt 120 (chief designer G.S.Efimov). This gun stands out for its length and power and was originally envisioned as a maingun of a perspective heavy tank that never appeared.

    This is probably the largest dedicated antitank gun ever built.

    Calibre 152 mm Rifled
    Breech type ?
    Firing mechanism ?
    Ordnance length 9045 mm
    Ordnance mass ?
    Barrel life ?
    Max Chamber Pressure ?


    ------------------------------------------------------------------------------



    Other Unknown Russian 152mm..

    Object 292

    [​IMG]

    The Object 292 test vehicle was produced by the Kirov Special Machinery Plant (Special Machinery, Limited), and the scientists at VNIITransmash. On the chassis of the T-80U they installed a new turret, a 152mm cannon, and some other parts. The turret and cannon were installed and in 1991, experiments began at Rzhev Poligon. Positive results were achieved.Ballistically, the smoothbore 152mm was far superior to the 125mm, though the chamber dimensions were not that much bigger. A new combat compartment was also developed, which could be installed on T-80 tanks without modifications to the main chassis structure.In September 1990 the tank was ready, and in 1991 on the Rzhev range have begun fire testing facility.All work was conducted under the leadership of chief designer, NS Popov. His deputy, twice winner of State Award, AK Dzyavgo, said: "We agreed with the Director of Central Research Institute of Nikolai Nikolaevich Hudkovsh on the implementation of ideas to develop a 152.4 mm in caliber.
     
  2. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    1. Barrel life of Rh 120 L/44 is 1,500 EFC, same as L/55 and M256.
    2. Maximum chamber pressure of Rh 120 L/44 and M256 is 7,100 bar
    3.The barrel per se of the Rh 120 L/44 weighs less than the barrel of the M256 due to the use different materials... why does the Rh 120 then weigh more than M256? May I ask where you took the weight values from? Do they include the gun mantlet?
    4. Jane's reported that the L/55 gun can support 500 bar more chamber pressure
    5. IMI tank gun has 7,250 bar maximum chamber pressure
    6. Ukranian KBA3 tank gun has a maximum chamber pressure of 6,500 kgf/cm², which is only 6,374 bar
    7. Likewise the KBM1M tank gun has a maximum pressure of 7,200 kgf/cm², which is only 7,060 bar
    8. The image of the 140 mm armed tank in the Swiss museum shows a Pz 87 WE with a RUAG 140 mm tank gun, which does not fire NATO 140 mm rounds, but shorter ones designed for human loaders.

    Is the Indian tank gun really that bad? Worst barrel life, smallest pressure limit and only 48 calibers long?
     
    Last edited: Jul 21, 2012
  3. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    Russian 2A83 152 mm Tank Gun

    [​IMG]

    Nizhny Tagil New Main Battle Tank, This vehicle is intended to become the new Russian MBT and was planned to enter service in 1994, but due to lack of financing it is still on the testing grounds (according to some reports it has cleared the testing phase around March 1999).The gun will be a 152mm smoothbore tank gun/ATGM launcher. The development of this system started as far back as end of the fifties for the heavy tanks (originally a rifled gun, probably M-69). The project was revived in the eighties and the gun was significantly redesigned. Even with ordinary powders a very high initial velocity of an APFSDS projectile is achieved. Some reports claim 152mm smoothbore gun that is carried by an elusive N.Tagil MBT is derived from 152mm M-69 "Taran" .

    Calibre 152 mm Smoothbore
    Breech type ?
    Firing mechanism ?
    Ordnance length 9045 mm
    Ordnance mass ?
    Barrel life ?
    Max Chamber Pressure ?


    --------------------------------------------------------------

    [​IMG]

    [​IMG]

    Rendered T-95..
     
  4. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    1.
    a.I have read L44 have worst barrel life with new gen rounds that is 260rnd, can you give me a link where it says L44 have 1500 efc,
    b.Besides the the gun is less thicker than L55 ( 130mm longer than L44 ) cannot have more than a 1000kg weight, hence it life is lower than L55..

    2.
    7100bars may be for M256 but need proof on L44 having same chamber pressure..

    3.
    Yes, the weight is not of the barrel but whole gun

    4.5.8
    Updated


    Regarding 6 & 7 names of the guns dont match.. ?
     
  5. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    Chamber pressure

    I have given the data clearly says 8000bars at max..

    proof pressure / safe pressure 6120bars..

    ------------------------------------------------------------------------------

    Caliber

    If calculate in maths of 48 caliber is 576cm

    Arjun Gun barrel length is 605cm to be a little more than 50cal..

    How is 48caliber ?

    ----------------------------------------------

    Barrel Life:


    Coz its a Rifled not smooth-bore..


    ----------------------------------------------------


    Indian Gun is good with max chamber pressure of 8000bars, of 50+caliber and in Rifled gun catagory it have 500rnd barrel life..

    Not bad for a Rifled Gun from 80s..
     
  6. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Really? I recommend you to take a look into literature and not to come up with some dubious informations from self-published websites. If you want a link and not the title of a book: here.
    260 rounds is realistic, for 120 mm DM 53 the German round with the highest barrel wear. 120 mm DM 63 is in the area of 400 - 600 rounds per barrel and for non-KE rounds it is 1,500. You are aware that EFC is a way of measuring via index? M829 equals 3 EFC, M829A1 equals 4 EFC, DM 53 equals probably 6 EFC. I originally also did not know the difference between EFC and real ammunition, but I was told different by literature and people in the internet.
    On the 2A46M tank gun used on the T-72M1 (including Indians) barrel life was 600 - 800 EFC or 100 - 200 APFSDS.

    Regarding the weight difference between L/44 and L/55: If "the whole gun system" also includes the mantlet (which is thicker armoured on Leopard 2A6) then 600 kg of the 1,000 kg difference could be part of the thicker armour.

    Really? Did you read any book about German tank guns and technology or the U.S. M256? According to Rolf Hilmes' "Kampfpanzer Entwicklungen der Nachkriegszeit" page 34 the Rheinmetall 120 mm gun has a maximum pressure of 7,100 bar. According to Steve J. Zaloga (M1 Abrams Main Battle Tank 1982 -1992) and R. P. Hunnicutt (Abrams A History of the American Main Battle Tank) the U.S. version of the Rh 120, the M256 does have the same performance; it is just simplified.

    Just a few posts above:
    http://defenceforumindia.com/forum/land-forces/39363-tank-guns-present-future-2.html#post539738
    http://defenceforumindia.com/forum/land-forces/39363-tank-guns-present-future-2.html#post539751

    Is that so? Then please provide your data. You wrote that "[t]he gun barrel has been partially autofrettaged to a pressure of 800 MPa to achieve a proof pressure of the order of 612 MPa" - this means that the gun has a maximum safe pressure of 6,120 bar, while it is autofregatted using a maximum pressure of 8,000 bar. It seems that you do not know how autofreggating is done, during autofregatting the barrel (and chamber) are under extremly pressure, which is higher than the maximum (safe) pressure of the later system. According to Rolf Hilmes (the book I mentioned above) the Rh 120 L/44 is autofregatted with a maximum pressure of 10,000 bar! Still the maximum (safe/operating) pressure of the gun afterwards is only 7,100 bar.

    There are different definitions of "barrel length". Some countries meassure the whole bore (meaning barrel and the chamber), some do meassure only the barrel part. The Russian 125 mm gun is therefore between L/48 and L/52. I thought that I read somewhere that the Arjun has a L/48 gun, however I am not sure where. Will search for the source...
     
    Last edited: Jul 21, 2012
  7. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    Btw: 3BM-9 equals 4 EFC and 3BM-22 equals 5 EFC according to Stefan Kotsch's website.
     
  8. methos

    methos Regular Member

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  9. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    A forum link ?

    That is forum link and some member giving chamber pressure which copied and pasted here by you.. ? !

    260 with advance rounds and 400-500rnds of other ammo ( No where mentioned its AP or other ) , there is no where written 1500rnds for L44 firing what ever round..

    Indian use 2a46M variant of its own for T-72M1, Pre one could fire 250rnds, the newer one can fire 600rnds for modern rounds..

    There is gov article was there on net, sadly corrupted..

    It does not Includes the Mantel, The mantel is part of tank mainly not a welded part of the Gun..

    The whole gun weight is excluding the mantel The barrel and other parts such as chamber and breech are counted..

    You have read the book:

    Explain me this, M256 was improve L44 ( I assume you agree ) Both gun are of different mass ( Exclude the Mantal ) M256 is heaver means stronger gun, Now how you explain this both have same 7100bars ?

    Have you gone what i told ?

    I said KBM2 , Not KBA3.. ?!


    So what is denial here ?

    Don't mix up Max Chamber pressure with imaginary 'MAX' safe pressure, DU rounds fired form M1A2 reach above 7100bars in M256..

    Scan the page from your book, I am not buying..



    ( I will wait for month if takes )
     
  10. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    He cites the TDV. That's best available source existing for German tanks. But you can also look at "Leopard 2 sein Werden und seine Leistung" by Paul-Werner Krapke. There the author mentions that barrel life is 550 rounds KE and that 1 KE round is equivalent to 3 non-KE rounds.

    Ok, I confused the names. But what I said stays the same. KBM2 has a pressure of 7,200 kgf/cm², which is 7,060 bar and not 7,200 bar. I

    No! The weight is not equivalent to performance under pressure. The U.S. chose different materials which are cheaper, but offer same performance at more weight. As written by Zaloga costs were reduced. See "M1 Abrams Main Battle Tank 1982 -1992" page 10. The M256 was improved, but U.S. found that the gun was "overly complex and expensive" (Zaloga literally).

    I don't mix anything up, you rather seem to. There are differences between the highest pressure used during production and the maximal supported chamber pressure in real firings (for example how fast the pressure grows to this level). Let's take a look at Jane's or the data from the manufacturer... not a single U.S. APFSDS exceeds 7,100 bar in the M256. M829A1 is having a chamber pressure of 5,600 bar according to Jane's, KEW-A2 (using the same propulsion unit as M829A2) has a pressure of 5,600 bar at 23° c.
     
  11. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    Dont give the book name, Its useless better give me scans..

    And i dont know what he cited coz i was not there..

    You see, Its written there just Rounds not KE or HE, What if 500rnds of HE ? not KE ..

    Done..

    Didnt i said, M256 is improved L44 ? Than only i said M256 is thicker and can endure more chamber pressure..

    you Are saying the opposite..

    Show me the link, Not forum like some real link..

    Or if you have book scan it ( I am here only )
     
  12. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    I don't have a scanner here, but I will see what I can do...

    It says KE ammunition there.

    Yes, you said so. But various authors say otherwise. Guess whom I believe...

    M829A1:
    ATK - Conventional 120mm Tank Ammunition: ATK's 120mm ammunition is the most advanced in the world
    120mm Tank Gun KE Ammunition
    + older brochure which cannot be assesed online anymore

    M829A2:
    http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA356146.. (see page 11), but that's not exactly the chamber pressure
    http://www.defmunintl.com/Brochures/120mm KE-W A2 APFSDS-T_DMI.pdf KEW-A2 is based on M829A2 (this is even said in the brochure) but equipped with a tungsten penetrator.

    For M829A3 no exact values are available, but the other rounds do not excede 7,100 bar. M829 is using the propulsion system of the early German rounds which have a pressure of 5,100 bar at 15°.
     
  13. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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    re: Tank Guns: Photo & Dicussion thread..

    Will see the Scans when ever you post here..

    No, I am saying what i read about M256..

    M829A1 is kinda old, I will give a read on A2 though, But i am sure i read somewhere here either its D90 or other that its more than 7100bars..
     
  14. methos

    methos Regular Member

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    re: Tank Guns: Photo & Dicussion thread..

    The file "Updated erosion modeling for the M829E3 round" includes a diagramm for gas pressure (again not necessarily chamber pressure, but it shows pressure in correlation to axial position - is an axial position of 0 m equivalent to the chamber?) at page 9. It seems that ~5,600 bar might at 23°c might be realistic for M829A3.
    The file also shows that U.S. pressure values are based on 23°c and not on a temperature of 15°c like German or Russian values.

    Also interessing is this phrase: "[...] that the current M256 cannon can fire less than 300 M829A3 rounds before being condemned."
     
    Last edited: Jul 22, 2012
  15. Scalieback

    Scalieback Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..

    Centurion Mark 1, 17 pounder
    [​IMG]

    Centurion Mark III, 20 pounder
    [​IMG]

    Centurion Mark V, 105mm
    [​IMG]

    Centurion AVRE, 165mm
    [​IMG]

    Centurion tank in Korea
     
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  16. Akim

    Akim Defence Professionals Defence Professionals

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  17. Kunal Biswas

    Kunal Biswas Member of the Year 2011 Moderator

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  18. Damian

    Damian Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..

    AFAIK Ukrainians have also one more, new gun besides Bagira, the second gun is 125mm Vityaz.
     
  19. militarysta

    militarysta Defence Professionals Defence Professionals

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    re: Tank Guns: Photo & Dicussion thread..

    Polish article about new german lightweight Rh 120LLR L/47 for light tanks, universal paltforms, tank destroyers, wheel tank destroyers, etc

    [​IMG]

    [​IMG]

    The most important dates in english:

    1. Rh 120LLR L/47 was developed for light tanks, universal paltforms, tank destroyers, wheel tank destroyers, etc
    It has the same baistic like Rh120 L44, but use JCB interfejs for progrmed munitions (like DM11)
    Its using material and technology originally developed for 140mm Rh guns.
    Barrel life time is:
    - 800-1400 for trening munitions (sabot/HEAT)
    - 600 for DM63
    - 200 for DM53

    efficiency muzzle brake is between 44%(DM53) and 55%
    the recoil is reduced from 650-700kN to only 250kN, and recoil impulse from 28-29kNs to 21kNs.

    2. For combat platform with weight about <20t. Rheinmettal developed diffrent gun: Rh 105SB cal 105mm whit recoil only 180kN and recoil impulse 16 kNs. Ammo using in that 105mm gun can penetrate 560mm RHA for 2000m.


    3. Rest dates is in the table - transating criteria in tabela for up to down:
    Kaliber[mm] - Caliber
    Długość lufy[mm] - barrel lenght
    Masy [kg] - mass (weight):
    - całkowita (tottal)
    - lufy (barrel)
    - zespołu zamka ( closing gun - I havent propoer word in english)
    - zespołu odrzutowego (recoil system)
    Objętość komory nabojowej [dm3] - (volume of the chamber for cartridges)
    Prędkość początkowa pocisku [m/s] - (V exit)
    Długość odrzutu [mm] - (recoil lenght)
    Maksymlana siła odrzutu [kN] (recoil strenght)
    Maksymlany impuls odrzutu [kNs] (recoil impulse)
    Maksymlane ciśnienie gazów [MPa] (maximum gas pressure)
     
    Last edited: Jul 22, 2012
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  20. Akim

    Akim Defence Professionals Defence Professionals

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