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8 hours ago, Pardus said:

Yet when RhM wrote of the Rh 130 and it's 50% increase in performance, they specified that increase as being in "penetration & effectiveness". 

 

Penetration doesn't scale linear to muzzle velocity - just look at the equation from Lanz & Odermatt. For the DM53, the increase in muzzle velocity when fired from the L/55 rather than the L/44 barrel is less than 5%; the improvement in armor penetration is quite a bit greater than 5%...

 

8 hours ago, Pardus said:

Well there are changes between the DM53 & DM63 projectiles, wether they are just superficial or new materials are used in the construction is unclear to me. But they are visibly different atleast in appearance, with the DM53's tip being all black whilst the in service DM63's I've seen are metallic with a black stripe.

 

Spoiler

m02006120800210.jpg

Qxe592U-fy_0shAEpr3i1m2rYO4czhwsa91GlWHR1454506307_titel-dm63.jpg

DM63 with black tip

 

 

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The Leopard 1A3's fire control system and optics were derived from the contemporary Leopard 2 development; in particular the EMES 12 steoroscopic rangefinder, the PERI R12 commander's sight and the FL

1976  Leopard 2AV armour(all from declassified reports), bustle spaced armour(12+30) also used on serial Leopard-2 tanks.

Interesting, from when is this document? Seems to be a very early array.     It doesn't matter how a layman, an enthusiasts or even a member of a tank crew rates the survivability of

20 hours ago, SH_MM said:

Penetration doesn't scale linear to muzzle velocity - just look at the equation from Lanz & Odermatt. For the DM53, the increase in muzzle velocity when fired from the L/55 rather than the L/44 barrel is less than 5%; the improvement in armor penetration is quite a bit greater than 5%...

 

I am well aware that penetration doesn't scale linearly with MV, hence why I said a 14.2% increase in MV jives well with a 20% increase in penetration.

 

The point is that RhM is talking about penetration when they refer to the percentage wise increase in performance with the Rh120 L55A1 & the Rh130 L51, and not KE. I think they made that clear in their press release:

25128747685_b2def23cc0_z.jpg

 

 

 

 

20 hours ago, SH_MM said:
  Reveal hidden contents

m02006120800210.jpg

Qxe592U-fy_0shAEpr3i1m2rYO4czhwsa91GlWHR1454506307_titel-dm63.jpg

DM63 with black tip

 

 

I had a feeling you would pull out those presentation pictures, problem is the actual in service DM63 doesn't seem to look like that, but rather like this:

 

c5lrvftwuaaeo29.jpg

ZSrypy_eW5g.jpg

 

pti9581svlb31.jpg?auto=webp&s=29d7c06d62

 

 

 

And here cutaways of the DM63 & DM53 (don't mind the length/width measurements, they are clearly just guesses, dimension wise DM53 & 63 look the same):

 

DM63

DM63.2.bmp

 

DM53

DM53+dwa.jpg

 

 

So like I said dimensionally there doesn't seem to be a discernible difference between the penetrators, but there is an outward difference in colour, which could indicate a different/newer tungsten alloy being used for the DM63 - or it could simply be a visual way of telling the two apart, we don't know.

 

 

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8 hours ago, Pardus said:

I am well aware that penetration doesn't scale linearly with MV, hence why I said a 14.2% increase in MV jives well with a 20% increase in penetration.

 

The source you referenced spoke about 2,200 m/s rather than 2,000 m/s though...

 

8 hours ago, Pardus said:

The point is that RhM is talking about penetration when they refer to the percentage wise increase in performance with the Rh120 L55A1 & the Rh130 L51, and not KE

 

Performance as in penetration scales linearly with KE, if the shape of the penetrator is designed to optimize it. As Rheinmetall doesn't measure penetration using steel, but rather focuses on complex armor arrays only (customers have to pay extra, if they want a test campaign against pure steel targets), it would be easier to achieve a 20% increase in penetration than actually achieving a 20% higher muzzle energy.

 

As stated in the presentation (which was not a press release, but a slide presented at an investors' conference), the 20% increase in performance is achieved by using the new gun with new ammunition. Willi Odermatt has published quite a few examples on how the maximum performance depends on factors such as rod length, velocity, diameter and material.

 

Even if it was possible for the new L/55A1 to accelerate the DM63's sub-projectile to a velocity of 2,000 m/s, it would be a lot better to design a longer and heavier rod, that would outperform the super-high-speed DM63 projectile despite its lower velocity.

 

8 hours ago, Pardus said:

I had a feeling you would pull out those presentation pictures, problem is the actual in service DM63 doesn't seem to look like that, but rather like this:

 

Three pictures from Turkish service...

 

Also, do you think DM53 will look identical to the presentation pictures?

 

2 hours ago, Pardus said:

Whilst going slower...

 

No, same performance at 15°C, where both projectiles have the same velocity. At higher temperatures, DM53 outperforms DM63 as its pressure rises faster. DM63 was not designed for maximum performance, but for safe firing in hot climates and for reduced barrel wear.

 

Over the whole qualified temperature spectrum, DM63's muzzle velocity differs by less than 100 m/s. DM53 OTOH isn't even qualified for hotter ambient temperatures than ~50°C.

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8 hours ago, SH_MM said:

Performance as in penetration scales linearly with KE, if the shape of the penetrator is designed to optimize it. As Rheinmetall doesn't measure penetration using steel, but rather focuses on complex armor arrays only (customers have to pay extra, if they want a test campaign against pure steel targets), it would be easier to achieve a 20% increase in penetration than actually achieving a 20% higher muzzle energy.

 

If the penetrator is modified to take advantage of it, yes. But the original premise was that the penetrator remained the same, and that it was only the propellant that was "hotter".

 

Anyway that the tanker might have been alluding to performance with the L55A1 was just a theory, one which you obviously don't agree with. Fair enough.

 

8 hours ago, SH_MM said:

Three pictures from Turkish service...

 

Also, do you think DM53 will look identical to the presentation pictures?

 

It certainly seems like it:

 

11008160-524882644318204-859512749-n.jpg

 

 

This difference in finish makes me wonder wether a new alloy could've been introduced from the DM63 onward to maintain performance similar to the DM53 at common european summer temperatures. The statement "Same high performance as DM53" could suggest this. Either that, or like I said earlier it's simply done so they're distinguishable without having to read the fine print on the SABOT. Not claiming either to be true, I am simply wondering since I find this sudden change perculiar.

 

ktICm1h.jpg

 

 

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18 hours ago, Pardus said:

If the penetrator is modified to take advantage of it, yes. But the original premise was that the penetrator remained the same, and that it was only the propellant that was "hotter".

 

No, this never was the original premise behind the development of the L/55A1 gun. As written in Military Technology (Wehrtechnik) issue 2/2017:

"Minor changes include an improved L55A1 gun, which will give 20% higher penetration capabilities with next-generation APFSDS projectiles, known as KE2020 (DM73)."

 

The 20% figure from Rheinmetall always has been based on the KE2020 round, even before the Leopard 2A7V variant with the L/55A1 tank gun was ordered for the Bundeswehr. The KE2020 prototypes feature longer, heavier rods (for example as reported by a Polish magazine in 2017 the DM73 prototype had a projectile weight of 10 kg vs the 8.35 kg of DM53/DM63) hence resulting in no major gain in velocity.

 

DM63+ was an after-tought to close the gap until DM73 is available. Given the delays of the Leopard 2A7V (contract delayed by years thanks to Rheinmetall and KMW not agreeing on workshare) and the fact, that apparently only 68 of them will actually feature the L/55A1 gun, the idea of adopting a DM63+ might have been just dropped.

 

18 hours ago, Pardus said:

This difference in finish makes me wonder wether a new alloy could've been introduced from the DM63 onward to maintain performance similar to the DM53 at common european summer temperatures. The statement "Same high performance as DM53" could suggest this.

 

None of that suggests anything regarding summer. The mean temperature in Germany is 10°C: https://de.statista.com/statistik/daten/studie/914891/umfrage/durchschnittstemperatur-in-deutschland/

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First test firing of hungarian Leopard-2A4. Now there is something interesting. They fired the guns with remote control, for "safety reasons" according to the video. (at 1:23) But why? 

Also it was mentioned that the tanks traveled to the firing range on public roads, this never happened here before. (usual stupid BS that steel tracks rip up the roads...)

 

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50 minutes ago, heretic88 said:

First test firing of hungarian Leopard-2A4. Now there is something interesting. They fired the guns with remote control, for "safety reasons" according to the video. (at 1:23) But why? 

 

 

 

A common thing to do. We did that too with our box fresh K9s.

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On 11/24/2020 at 5:29 PM, SH_MM said:

None of that suggests anything regarding summer. The mean temperature in Germany is 10°C: https://de.statista.com/statistik/daten/studie/914891/umfrage/durchschnittstemperatur-in-deutschland/

 

Well I did find this:

0sDUuT.png

Seems to say that DM63 has the same performance as the max of the DM53? 

 

The possible 80 m/s increase in MV is also interesting, and makes you wonder wether this is what has been achieved with the DM63A1.

 

 

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1 hour ago, Pardus said:

Seems to say that DM63 has the same performance as the max of the DM53? 

Same performance at +15°C...

t78w2cD.png

https://web.archive.org/web/20101220161356/http://rheinmetall-defence.com/pdfengine/product.php?fid=1465&lang=3

 

You can use the web.archive.org for Rheinmetall's website to verify this. This exact screenshot is taken from a pdf generated using the 2010 version of the website. As the internet wayback machine of web.archive.org is a little bit unstable, the link might not work on the first try.

 

The additional 80 m/s velocity is possible when raising the chamber pressure; the DM63A1 is designed to also work with weaker gun systems (i.e. the old Leopard 2A4 tanks that do not have the new gun brake), increased chamber pressure would prevent these from using DM63A1.

 

The KEW-A3 APFSDS and M829A4 use the SCDB technology to achieve greater muzzle velocities, but operating at a higher chamber pressure at 21°C (but due to the fact that SCDB is temperature-insensitive, these rounds won't exceed the pressure limit at higher temperatures). This option was suggested by Rheinmetall Nitrochemie about 18 years ago, but not taken.

 

mrequCY.png

 

 

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The KEW-A3 APFSDS and M829A4 use the SCDB technology to achieve greater muzzle velocities, but operating at a higher chamber pressure at 21°C (but due to the fact that SCDB is temperature-insensitive, these rounds won't exceed the pressure limit at higher temperatures). This option was suggested by Rheinmetall Nitrochemie about 18 years ago, but not taken.

 

Well TIPS is SDCB based according to RhM, so not sure I follow?

 

Is there any documentation which describes exactly what the difference between DM63 and DM63A1 is?

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On 11/25/2020 at 8:05 PM, Pardus said:

 

Well TIPS is SDCB based according to RhM, so not sure I follow?

 

Is there any documentation which describes exactly what the difference between DM63 and DM63A1 is?

 

RH guy, when asked, stated that A1 got new primer, that meet more strict requirements on electromagnetic radiation hazards.

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