Main Battle Tanks and Armour Technology

[militarysta]

What are known differences between 478DU9-1 and 478DU10?

We know that 478DU series are from 478DU1 to 478DU10, but I heard that differences between most of them are not known or minor.

You have PM on milits.pl - there is answer

 

[militarysta]

New opus:





Fist tabe (and picture):
German, US and Soviet/Russian APFSDS penetration table. I tryied to find and placed in table two penetration values:

a) (A) achievable penetation value - it's the biggest value in found in most reliable sources
b) (B) guaranteed penetation value - it's guaranteed penetration value found in some sources
What interesting - older Russian sources distinguish diffrence between both kind of perforation - this table was on btvt some yers ago and on Frontanow page. For Germans ones I posted just diffrense between WITU and other sources - in My opinnion it's just diffrence between this two perforation values. For US rounds its just assumption based on both (German and Soviet ones) cases.
But what is funny - this diffrence between both penetration values - achievable and guaranteed explain most of discrepancy between values in sources.
Ex: 810mm RHA for DM53 for 2000m and 750mm RHA for the sam round for 2000m. 470mm for DM-33 for 2000m (WITU) and 540mm for DM-33 (rest sources).


Second two pictures is one table (for hosting reson Im split it out) - Soviet- Russian/Ukrainian and German tanks armour level and ammo penetration values is presenting there.
For Leopard-2 armour protection is my estimation - based on rather strong premises (I was explain it erlyier), for T-72M1 and T-72B is well know in many sources. T-80U is my own estimation. Dates for Ob188A1(T-90A) and Ob.188M (T-90MS) are taken for...this funny presentation T-90MS and values give on it - whit assumption about Relikt (1,5) and Kontakt-5 (1,2) protection.

Full table (all in one) is here (9MB):
Download MBT 2012 porównanie finnal3.bmp from Sendspace.com - send big files the easy way

 

[Damian]

Militarysta, will You expand this for more MBT's?

 

[methos]

I don't really think that this is correct.
If you come up with guaranteed and achievable penetration values, then these should really be values based on real data and not from researches. It also should depend on the exact scenario (e.g. which type of steel is used at which temperature and what is the angle of impact). According to the Lanz-Odermatt equation the difference between impact angle 0° and 60° can be more than 100 mm LOS penetration, i.e. in the area of 1/5 to 1/7 of total penetration.

I mean take a look at the 120 mm DM 13. It is not a very high-tech round, using a two-part penetrator in a steel body. BUT this is still 6 years ahead in design than Soviet tank rounds, which originally used steel (density ~7.85 g/cm³) penetrators which were then fitted with a small slug of WC (density 13 g/cm³) - WHA as used on DM 13, M735, M111 etc. had a denisty of about 17.5 g/cm³ -> shorter WHA penetrator can penetrate more armour. Even though the muzzle velocity is significantly smaller (but the vdrop is also) DM 13 should penetrate more armour than contemporary Soviet ammunition (i.e. 3BM-22 Zakolka). If we take a look at projectile design DM 13 has a more than 150 m/s higher muzzle velocity than M735 and M111, which are both said to penetrate 300 - 350 mm at 2,000 m. DM 13 will likely have a higher velocity at 2,000 m than M735 and M111 have at the muzzle, so penetration should be far more than 330 mm at 2,200 m. I doubt that "380 mm at 2,000 m" is "achievable penetration". Likewise penetration values of other rounds (especially DU rounds) is disputable. In fact there exist no formula explicitly made to calculate the penetration values of DU rounds. There are no datapoints.
L-Z equation was modified to match reported/estimated performance of DU rounds, modifications to it done to caluclate penetration of DU are not based on real tests.
M829 was introduced in 1987? How comes that the first 120 mm gunned M1(A1) was introduced in 1984?
Some values are freaky... for example the value "840 mm achievable penetration" for M829A3... is this based on the the TankNet thread discussion the performance of the M111 Hetz APFSDS? There the value 840 mm is based on very soft steel (230 HB, not the common RHA definition) and is based on an sloped target - by Lanz-Odermatt equation this would correspond to ~780 - 800 mm in 270 HB steel (for same angle) and only to ~690 mm into 270 HB at 0° impact angle thanks to the ridicously great difference between sloped and non-sloped impact in L-O equation.
I believe that DU rounds are overestimated. Yes they have adiabatic shearing... but that's it. At the same time they also have a greater diameter.
One example:
M829A1 has a 4.6 kg penetrator but a diameter of 25 (penetrator only 22 mm). 120 mm DM 43 has a penetrator weight of "approx. 4 kg" and a diameter of ~21 (20.7 measured by me on brochure image from KEW-A1, penetrator diameter is unknown). If we take a look at the energy values we will see that the penetrator of M829A1 has a muzzle energy of 5.704 MJ, while the penetrator of DM 43 has roughly (because of low information of weight) a muzzle energy of 6.055 MJ (this is for 4 kg, unless "approx. 4 kg" includes 3.7 kg DM 43 will always have more muzzle energy). Per area (based on the diameter of projectile because we have no informations about the diameter of the DM 43 penetrator) this will be 0.017 MJ per mm² for DM 43 and only 0.012 MJ per mm² for M829A1. Even if the muzzle energy of the DM 43 penetrator would be the same, the area on which the M829A1 impacts is still 41% larger! Some energy will be spent during penetration on generating heat or sound, but we don't have enough information about this - let's just ignore this. If the mushrooming (which is not exisiting to the same degree on M829A1 due to adiabatic sheer) increases the surface by more than 41%, then M829A1 could outperform 120 mm DM 43 (at the muzzle). Even worse gets the situation if we take a look at 2,000 m. M829A1 deaccelerates faster than DM43. I don't want to proclaim that the shorter German ammunition is better than M829A1, but I see no reason to assume that M829A1 is better. Likewise comparision between later German and U.S. ammunition can not provide any reason why U.S. ammunition is superior, except the magical adiabatic sheer [which can also achieved with tungsten alloys, question is if this can happen under battlefield conditions or only in laboratories).
So either my approach for estimating performance without using RHA values is wrong, or the estimated penetration values based on modificated equation made for tungsten rounds is wrong (or has been manipulated).

Fofanov reported Svinet's values higher (i.e. 650 mm (a) and 600 mm (g)).

T-72 has 350 - 475 mm thick cast steel turret (first value for turret center around mantlet, later value for turret "cheeks") according to CIA reports. That will be for a TE of 0.85 to 0.95 for cast steel a protection level of 297 - 403 to 332 - 451 mm RHAe (with most of the turret being ~400 - 451 mm RHAe). If the T-72A turret is (as claimed on TankNet and other forums) the same but with an additional filler (ca. 13 cm) of composite armour, then the turret should be having a max. value higher than 475 mm RHAe.

 

[militarysta]

I don't really think that this is correct. .

Well, You know - when I tried to make some synthesis I must choose comparison methodology. Counting it from formula looks nice but it's impossible - to many rounds to few dates. For me only way was analysis dates posted in many sources:
a) WITU pdfs.
b) btvt
c) Frontanov
d) otvaga % TankNet
e) periodicals about military
etc.
And there was huge discrepancies - how explain that DM53 from L-55 have sometimes 810mm RHA (in two polish sources and in one Yours) but most of the sources give us "only" 750mm RHA? Tha same about DM33A1 -this round was tasted many times in Poland and all sources conected from testing institutes gives it only 470mm RHA. But all other sources give it ~540mm RHA. And from most of that ammo was the same problem. And it's possible to exlain when we checkt diffrences between achievable and guaranteed penetrations values. For russian rounds it was easy becouse three independent sources from east gives both kind of penetration -so I just copy it.
Americans M829 familiy is just overestimated -and I agree with that. And again - Russian NII Stali, TACOM, and dates from Lanz-Odermatt formula are diffrent on about 80mm RHA fo ex M829A1.
So I had to choose from many dates.

 

[Damian]

The big mistake You both do here is that You do not know the properties of materials from which modern APFSDS ammunition is made. We do not know nothing about DU alloys used by Americans, neither about German Tungsten alloys.

In fact the whole comparision between DU and WHA comes with wide known civilian data, and known properties with ignoring what we do not know, and if we do not know, IMHO we should not make any estimations with such a big black hole in data.

But it's just my opinion... and I doubt that goverments and manufacturers will share with us such data.

 

[methos]

The difference between 810 mm and 750 mm is only 8%. That's not very much - it could be a result of different RHA definition (i.e. harder steel), different estimates for penetrator length, different estimates for diameter or different estimates for density. It also could be result of including some sort of shearing characteristics or other advantages in penetrator material. I can only recall that the older WITU files even assumed a penetration as low as 550 mm at 2,000 m when fired from the Rh 120 L/44 gun - that's why I somehow have my doubts regarding their statement. Similarly people on TankNet assumed a penetration of 960 mm at 2,000 m for M829A3, when they didn't knew that the muzzle velocity was reduced when compared to M829A2 instead of increased. For 120 mm DM 53 and the L/55 tank gun some people expected a muzzle velocity of 2,000 m/s and came up with a penetration value of 1,000 mm RHA at 3,000 m!
In one book the author says that 120 mm DM 53 when fired from the L/55 tank gun can pierce about twice as much as the earlier rounds - but does not mention which. When it is 120 mm DM 13, then penetration would be ~760 mm at 2,000 m - but he uses the plural implying that this statement can not be reduced only to 120 mm DM 13 - If we include 120 mmDM 23, then it should be between 760 mm and ~850-900 mm at 2,000 m, if the author is correct.


Damian: That is more or less what I mean, just with looking at a different aspect. What I try to say is that German ammunition (and also that of some other countries) is superior to the U.S. DU ammunition, if we exclude the point of adiabatic sheer. We do not have proper data about the materials, but reported values for weight, velocity and shape.
A 4 kg penetrator with a smaller at 1,740 m/s is better than a 4.6 kg penetrator at a velocity of 1,575 m/s - as long as the 4 kg penetrator does not have a greater diameter (and data shows that it does not have). If we compare 120 mm DM 53 fired from the L/44 gun and M829A2, we see that they both are pretty close. M829A2 is 10 m/s faster and 4 cm longer (not necessarily in penetrator length), but has also a 3-4 mm greater diameter, which means that the energy per surface is actually lower, because the penetrator weight is nearly the same.

Fact is that both IMI and Rheinmetall, as main developers of tungsten ammunition, claim that their latest rounds have improved performance due to the use of better alloys. How much better is unkown to us. One example is the presentation "Advanced Penetrator Materials" - there three different tungsten materials (conventional, adiabatic-shearing and a nano-composite) are compared with DU. None of the alloys achieves the same performance (which also may be due to the lower densities), but the adiabatic-shearing tungsten is far superior to the conventional one, while the W-nano-composite is even better than the shearing tungsten.
The question is how much advantage does DU have? It is possible to create tungsten alloys with a density as high (or even higher) than DU - and based on caluclations the typical density of only 17.5 g/cm³ does not fit for modern APFSDS rounds - and it is possible to increase performance by using a shearing or nano-composite alloy.
So coming up with higher penetration values for DU rounds without knowing how large the advantage of DU is (and without knowing if there still is an advantage of DU) seems somehow biased.

 

[militarysta]

IMHO we should not make any estimations with such a big black hole in data.

Well - thats the reson, why I used only dates from some sources (Russian sites, WITU, periodicals etc) and try to not count it by myself Result is in the table, and of course there must be some mistake - the strongest part of this table are Russian APFSDS and Germans (from DM-33 do Dm53). US APFSDS are rather not relevant here.

Militarysta, will You expand this for more MBT's?

In next week I will made the same table, but for HEAT (SC).

Other tanks? Well it's amoust impossible now - we know ony three-four facts about M1 and CR2 armour protections. And it's not enought unfortunatly...
This values in table (abour tank protection v. AFSDS) IMHO are rather good. Soviet -Rusian/Ukrainian tanks are rather good know (in armour thema) - thanks for "holly war" between UVZ and Charkiv, and test in NATO countries (Poland, Germany, USA, France, etc) so just it was possible to have proper dates (T-72B) or rather correct (rest of T- serie). For Leopard-2 family dates are made by me and I know there are diffrent then rest dates in internet, but I preety sure what I posted in that thema.

 

[Kunal Biswas]

New opus:

@Militarysta

There is no IMI APFSDS here, Do you have any estimate of this new IMI round..

http://www.imi-israel.com/vault/documents/m338.pdf

 

[Damian]

The difference between 810 mm and 750 mm is only 8%. That's not very much - it could be a result of different RHA definition (i.e. harder steel), different estimates for penetrator length, different estimates for diameter or different estimates for density. It also could be result of including some sort of shearing characteristics or other advantages in penetrator material. I can only recall that the older WITU files even assumed a penetration as low as 550 mm at 2,000 m when fired from the Rh 120 L/44 gun - that's why I somehow have my doubts regarding their statement. Similarly people on TankNet assumed a penetration of 960 mm at 2,000 m for M829A3, when they didn't knew that the muzzle velocity was reduced when compared to M829A2 instead of increased. For 120 mm DM 53 and the L/55 tank gun some people expected a muzzle velocity of 2,000 m/s and came up with a penetration value of 1,000 mm RHA at 3,000 m!
In one book the author says that 120 mm DM 53 when fired from the L/55 tank gun can pierce about twice as much as the earlier rounds - but does not mention which. When it is 120 mm DM 13, then penetration would be ~760 mm at 2,000 m - but he uses the plural implying that this statement can not be reduced only to 120 mm DM 13 - If we include 120 mmDM 23, then it should be between 760 mm and ~850-900 mm at 2,000 m, if the author is correct.


Damian: That is more or less what I mean, just with looking at a different aspect. What I try to say is that German ammunition (and also that of some other countries) is superior to the U.S. DU ammunition, if we exclude the point of adiabatic sheer. We do not have proper data about the materials, but reported values for weight, velocity and shape.
A 4 kg penetrator with a smaller at 1,740 m/s is better than a 4.6 kg penetrator at a velocity of 1,575 m/s - as long as the 4 kg penetrator does not have a greater diameter (and data shows that it does not have). If we compare 120 mm DM 53 fired from the L/44 gun and M829A2, we see that they both are pretty close. M829A2 is 10 m/s faster and 4 cm longer (not necessarily in penetrator length), but has also a 3-4 mm greater diameter, which means that the energy per surface is actually lower, because the penetrator weight is nearly the same.

Fact is that both IMI and Rheinmetall, as main developers of tungsten ammunition, claim that their latest rounds have improved performance due to the use of better alloys. How much better is unkown to us. One example is the presentation "Advanced Penetrator Materials" - there three different tungsten materials (conventional, adiabatic-shearing and a nano-composite) are compared with DU. None of the alloys achieves the same performance (which also may be due to the lower densities), but the adiabatic-shearing tungsten is far superior to the conventional one, while the W-nano-composite is even better than the shearing tungsten.
The question is how much advantage does DU have? It is possible to create tungsten alloys with a density as high (or even higher) than DU - and based on caluclations the typical density of only 17.5 g/cm³ does not fit for modern APFSDS rounds - and it is possible to increase performance by using a shearing or nano-composite alloy.
So coming up with higher penetration values for DU rounds without knowing how large the advantage of DU is (and without knowing if there still is an advantage of DU) seems somehow biased.

I agree. But remember that Americans are working on DU alloys longer than anyone else, and they are working on them for at least two different aplications in military (ammunition and armor protection).

So if Germans and Israelis were capable to do progress in WHA alloys, why not Americans could do the same progress in DU alloys?

Besides we have here the magical word - alloy, what this means is, that we civilians (and even military guys not close to the R&D) do not know, how exactly these alloys are done, what is "cooperations" of different materials used in one single alloy.

You remember when we were discussing armor protection of different tanks, and both made a correct point that for example people talking about M1 Abrams series tanks DU alloy armor, mostly forget that DU is only one single component of armor, encased in several different materials, making the whole armor package, and that DU is not a single, "magical" material making the protection, but a component that is working together with other components to achieve protection levels demanded by US Armed Forces.

Of course such correct in my point of view argument, is correct for any other armor design, and not only armor design but also ammunition.

IMHO the biggest problem with all estimates, be it regarding to armor or ammunition, are mostly focused on one single element, or several elements, but are oversimplified (be it because of lack of data or because their authors, lack of knowledge or other reasons) and thus not correct.

So for now, IMHO the best consensus for this is to say, that most modern and best APFSDS ammunition is comparable in performance, not the same, but comparable. Same can be said about armor protection of the most modern and best Main Battle Tanks (of course excluding weak zones and such things like a specific design of vehicle making some of it's parts not better or worse protected).

I think anyone would agree.

 

[Godless-Kafir]

Wondering how much it would take to slap on composite side armor in Arjun turret in case of urban conflict? Can they remove the tool box and slap on armor if needed!

Anyone has a clue on this?

 

[methos]

The U.S. might have also worked at DU, but what exactly should they have changed? It is true that there are more differences between "having adiabatic shear" and "not having adiabatic shear" - but these differences are smaller. You can change the exact strain required for shearing... but what else? I do not know if other characteristics of adiabatic shear can be affected.
The material characteristics like (yield) strength or ductility can also be affected by changing alloy, this is what was probably done on M829A2 to better perform against ERA.

We know the composition of various older/experimental tungsten alloys and older DU alloys (e.g. of M829/M829A1 and if TankNet claims are correct also M829A1). We know from various research papers and reports that some DU alloys have a density of 18.5 or 18.6 g/cm³. The problem is that a high density is relevant for penetration (i.e. higher density = higher penetration), but DU has to be alloyed to have better material characteristics. DU is probably ~95 - 97% of the weight. U.S. 105 mm APFSDS and M829/A1 used titanium as sole other alloy element. M829A2 has according to TankNet as sole other alloy element vanadium. The presentation "Advanced Penetrator Materials" does include three different Uranium alloys, with U-3/4Ti being used in M829(A1) and U-2.1%V probably in M829A2.
More alloy ingredients mean less density, i.e. less penetration; so probably there is still ~95% DU and only a very small part of other material.

Tungsten alloys however have a density of 17 - 17.5 g/cm³ for the older military alloys used in APFSDS (typically only 90% of the alloy is tungsten, because it is to iirc. brittle on it's own). Other materials are typically iron (FE), nickel (Ni), cooper (Cu) or cobalt (Co), but Co is not good for the environment/humans because it is somehow poisionous and some texts therefore mention that it is not used anymore. Also aluminium is sometimes used, but it seems to be very rare in WHA.
There is simply more room for improvments in tungsten alloys. The conventional alloy mentioned in the presentation "Advanced Penetrator Materials" has a compostion of 90 W - 9Ni - 1Co... this is inferior to the alloy 93W - 4.9Ni - 2.1Fe in "Adiabatic shearband in WHA in high-strain-rate compression" which achieves adibatic shear at very high strain rates. Some Japenese website I read (translated by google translator) suggested using tantalum instead of nickel or iron, i.e. a material with a density of 16.65 g/cm³ instead of 7.8 - 8.9 g/cm³ for iron and nickel.
The adiabatic shearing alloy mentioned in "Advanced Penetrator Materials" has a W content on of only 80%, with 20% being an hafnium alloy... so a W alloy less prone to adiabatic shearing (but still capable of) might perform better at higher strain (meaning higher velocity). And Isreali and German APFSDS tend to have a higher velocity than their U.S. or British counterparts.

If we take a look at latest generation APFSDS and try to calculate density based on reported weight values and the penetrator shape, then it seems to be always denser (e.g. 18 - 18.4 g/cm³) than 17.5 g/cm³.

 

[Damian]

Wondering how much it would take to slap on composite side armor in Arjun turret in case of urban conflict? Can they remove the tool box and slap on armor if needed!

Anyone has a clue on this?

It depends.

Can the mounting points for a simple tool boxes hande more weight of an armor module?

If yes, then the only thing to do is to develop armor modules with attachements matching mounting points for tool boxes.

However such armor modules might be more vurnable to mechanical damage and it might be possible that stronger explosion might rip off such armor module from it's attachements. It might be a difficult problem to overcome, even if it is looking simple.

 

[Godless-Kafir]

It depends.

Can the mounting points for a simple tool boxes hande more weight of an armor module?

If yes, then the only thing to do is to develop armor modules with attachements matching mounting points for tool boxes.

However such armor modules might be more vurnable to mechanical damage and it might be possible that stronger explosion might rip off such armor module from it's attachements. It might be a difficult problem to overcome, even if it is looking simple.

Or they could just weld it on, welded joints typically are more stronger than cast ones.

 

[Damian]

The U.S. might have also worked at DU, but what exactly should they have changed? It is true that there are more differences between "having adiabatic shear" and "not having adiabatic shear" - but these differences are smaller. You can change the exact strain required for shearing... but what else? I do not know if other characteristics of adiabatic shear can be affected.
The material characteristics like (yield) strength or ductility can also be affected by changing alloy, this is what was probably done on M829A2 to better perform against ERA.

We know the composition of various older/experimental tungsten alloys and older DU alloys (e.g. of M829/M829A1 and if TankNet claims are correct also M829A1). We know from various research papers and reports that some DU alloys have a density of 18.5 or 18.6 g/cm³. The problem is that a high density is relevant for penetration (i.e. higher density = higher penetration), but DU has to be alloyed to have better material characteristics. DU is probably ~95 - 97% of the weight. U.S. 105 mm APFSDS and M829/A1 used titanium as sole other alloy element. M829A2 has according to TankNet as sole other alloy element vanadium. The presentation "Advanced Penetrator Materials" does include three different Uranium alloys, with U-3/4Ti being used in M829(A1) and U-2.1%V probably in M829A2.
More alloy ingredients mean less density, i.e. less penetration; so probably there is still ~95% DU and only a very small part of other material.

Tungsten alloys however have a density of 17 - 17.5 g/cm³ for the older military alloys used in APFSDS (typically only 90% of the alloy is tungsten, because it is to iirc. brittle on it's own). Other materials are typically iron (FE), nickel (Ni), cooper (Cu) or cobalt (Co), but Co is not good for the environment/humans because it is somehow poisionous and some texts therefore mention that it is not used anymore. Also aluminium is sometimes used, but it seems to be very rare in WHA.
There is simply more room for improvments in tungsten alloys. The conventional alloy mentioned in the presentation "Advanced Penetrator Materials" has a compostion of 90 W - 9Ni - 1Co... this is inferior to the alloy 93W - 4.9Ni - 2.1Fe in "Adiabatic shearband in WHA in high-strain-rate compression" which achieves adibatic shear at very high strain rates. Some Japenese website I read (translated by google translator) suggested using tantalum instead of nickel or iron, i.e. a material with a density of 16.65 g/cm³ instead of 7.8 - 8.9 g/cm³ for iron and nickel.
The adiabatic shearing alloy mentioned in "Advanced Penetrator Materials" has a W content on of only 80%, with 20% being an hafnium alloy... so a W alloy less prone to adiabatic shearing (but still capable of) might perform better at higher strain (meaning higher velocity). And Isreali and German APFSDS tend to have a higher velocity than their U.S. or British counterparts.

If we take a look at latest generation APFSDS and try to calculate density based on reported weight values and the penetrator shape, then it seems to be always denser (e.g. 18 - 18.4 g/cm³) than 17.5 g/cm³.

But You should also remember against what such ammunition is designed for. Faster penetrator with smaller diameter might not be the best solution against modern composite and dynamic protection. We should take in to account that modern armor protection, even composite armors, today use reactive or dynamic elements in their design. So velocity might not be answer here, neither smaller diameter making penetrator more vurnable to bending, yaw and similiar phenomena.

This is also the problem I pointed out some time ago, the focus on RHA and RHAe values, that are not nececary correct to messure protection potential of modern protection.

So if on paper against RHA tungsten penetrators might look better in theory, in reality situation might be opposite.

Or they could just weld it on, welded joints typically are more stronger than cast ones.

Yes this might be a solution, to just take out storage boxes, weld there steel plates to form a composite armor cavity and place in it composite armor package. Storage boxes might be then placed there on armor.

But You made on mistake here, not welded joints are stronger than cast ones, but a rolled armor plate is stronger than a cast armor element of the same thickness and hardness.

 

[methos]

This again leads to a question for which I don't know the answer: What is better: a thick but slower penetrator or a thinner but faster one? E.g. If you strike a reactive armour sandwhich, then the slower one will have a large surface of interaction (more rubber is directly compressed and more steel will hit the penetrator when the rubber decompresses) and the interaction will take longer. Alternatively the smaller but faster penetrator is in danger of breaking (or bending, according to TankNet DM 53 is designed to bend instead of breaking, when hitting Kontakt-5). I do not have any sources implying one or the other is better against composite armour.

 

[Damian]

Yes this is a problematic question, and I doubt we will find out what is better solution anytime soon.

 

[Akim]

This again leads to a question for which I don't know the answer: What is better: a thick but slower penetrator or a thinner but faster one? E.g. If you strike a reactive armour sandwhich, then the slower one will have a large surface of interaction (more rubber is directly compressed and more steel will hit the penetrator when the rubber decompresses) and the interaction will take longer. Alternatively the smaller but faster penetrator is in danger of breaking (or bending, according to TankNet DM 53 is designed to bend instead of breaking, when hitting Kontakt-5). I do not have any sources implying one or the other is better against composite armour.

I already wrote to Damian, that now between western and soviet school ammunitions a compromise is attained. But Israel went out forward, obtaining hypersound constant-speed of shell to 5 km. And there mass of not play role. More important speed!

 

[Kunal Biswas]

Russian 120mm tank gun, Prototype ?

 

[Damian]

Designed for export, Russian will stick with 125mm smoothbores for a while.