A question about Main Gun ammo

[Invader ZIM]

Hey guys,

I looked in the SB Wiki, and searched the forums but couldn't find any specifics I was looking for about the main gun ammo used in SB.

What I mean: Is there some kind of table that would give me an idea of armor penetration at 2000m for each type of ammo? As opposed to the data in the sim which gives penetration at the muzzle? Is it possible to find out how fast the penetration drops for each round by time it gets out to 2km? And does DU ammo in the sim behave any differently than the Tungsten penetrators being simulated?

[Eisenschwein]

Sorry for being in German:

http://www.kotsch88.de/m_120_mm.htm

[Invader ZIM]

Thanks for that Eisenschwein, that's actually the first site that I've seen that shows nice cross sections of the Tungsten rounds that Europe uses.

Don't apologize for it being in German lol, I was able to translate it

But it doesn't seem to answer my question, as there's no estimate of armor penetration.

In Steel Beasts Pro, there's a good table of at the muzzle penetration when selecting ammo in the mission editor, but I was looking for a table for the penetration at say 2000m for each round available.

[dejawolf]

http://fofanov.armor.kiev.ua/Tanks/ARM/apfsds/ammo.html

[Invader ZIM]

Thanks Dejawolf, that covers the Russian ammo penetration at 2km.

Is there an equivalent site like that for European and US ammo at 2km?

[Grenny]

You are aware that this is data covered in the firing-tables of the different ammo-types.

These tables are classified/resticted. and I dare anyone posting them here!!!

[Invader ZIM]

Well, yea I understand that Grenny, but what I'm asking for is the public data or guesstimates of what the ammo is doing in our Simulator. Not the classified real world values.

[Eisenschwein]

With the given Data it possible to calculate it:

P= (1,044·V0,194·ln(LD)0,209)·L·S·M

Dabei ist:

D den Durchmesser des Penetrators in mm,

L die Länge des Penetrators in mm,

M den Materialfaktor,

P die Eindringtiefe in gewalzten Panzerstahl in mm,

S den Skalierungsfaktor,

V die Aufschlaggeschwindigkeit in km/s,

Or use this:

http://www.longrods.ch/perfcalc.php

;-=

[Invader ZIM]

That's pretty neat, thanks Eisenschwein!

[Tjay]

So when you see a target do you check the ammo type and run the appropriate calculation before firing or not - depending on the result?

[Invader ZIM]

LOL, nice one Tjay.

Actually it's more for scenario design. I'm trying to create a scenario with T-80U and T-72Bs using the BM-32 and BM-42 ammo, as I understand these are more common rounds, but need to get an idea of how fast the rounds penetration falls off around 2km. The site Dejawolf came up with is a really good reference for that.

But now I'm faced with the same problem with M1's and Leopard 2's. I'm trying to set up so the usual range of engagement happens at 2km, and I don't want to give them a round that's too weak at 2km, but one thats not too powerful either.

Sort of forcing the player to use more maneuver instead of being able to blast them head on without thinking about armor protection.

[Eisenschwein]

Oh, that Prob. is simple to manage.

Don´t give them weaker Ammo, lower the load of Ammo.

In SB everyone will start Fire when he see the ENY, they don´t care about the effectiveness of the ammo at this Range.

In RL that´s A different Thing.

But I´ve they see: Uuuuh just 50% of Ammo loaded, they think twice ;-=

[Invader ZIM]

Hehe, that's a good idea Eisenschwein, I always have a habit of cramming every vehicle with the maximum amount of ammo I guess. So I can cut the ammo for the player vehicle at least.

But what about other AI controlled units for both sides? Since they don't think about their ammo load and just fire when they get in range, it wouldn't make sense to cut their supplies.

[Grenny]

Just use the "open fire if" condition.

There you can set the maximum range at which the AI will open fire.

Of course, as soon as they come under fire, they'll return it no matter what range.

[Invader ZIM]

Thanks Grenny,

I thought that they would not return fire until they got within the set range, even if you started firing on them before their set range, so that clears that up for me.

Oh, I did find a site that had all the estimated penetration values at a 2km range. They were here, about halfway down that page:

http://collinsj.tripod.com/protect.htm

Don't know how accurate they are, but they seem reasonable if you go by the listed muzzle penetration values in Steel Beasts. Might help someone else for a rough guide for their ammo selection.

[Ssnake]

You could of course make a scenario where you have a number of Blue T-72s with different ammo types loaded in unlimited number, and park many blue M1s and Leopards at the desired distance in a semi-circle around those T-72s. Activate the "Remove when killed" option.

Then simply shoot the tanks with the various ammo types and check in the AAR which ammo types did some actual damage, and which did not.

[Maj.Hans]

After reading the Kotsch website, I have to say I really don't understand how/why DM13A1 was produced when it's hardly better than DM13, and the DM23 looks like it's only a minor change from DM13 yet with much better penetration?

[Invader ZIM]

Thanks for that Ssnake,

Great thing about the mission editor is that there's usually multiple solutions for any given problem. I just need to be a little more imaginative

[Ssnake]

After reading the Kotsch website, I have to say I really don't understand how/why DM13A1 was produced when it's hardly better than DM13, and the DM23 looks like it's only a minor change from DM13 yet with much better penetration?

Look at the introduction dates. DM13 is a 1978/79 round to enter service with the new 120mm gun, and in comparatively small numbers as only about 100 or 150 tanks were made each year; the M1 received the 120mm gun only years alter. In those days, the Leo 2 was the only tank with a 120mm smoothbore cannon.

Once introduced, actual research & development was started to make the rounds better, and to gradually reveal to NATO allies the potential of this new gun. Keep in mind that this was actually the start of the entire long rod design process - or at least the point in time when it started to gather a lot more momentum. A few years before - actually, until about the date when composite armors were developed in the mid 1970s - everybody thought that hollow charge rounds were the ammunition of choice to defeat armor and that kinetic energy rounds were a design of the past - with some more life squeezed out of them with the introduction of dU and sabots.

Especially getting around the problem of getting the long rod darts out of the gun tube without breaking up from the launch stress and vibrations was something not very well understood at the time. Also, bigger diameter means bigger effect behind the armor, provided that you actually manage to fully perforate of course.

The A1 variant was probably just a change in the production process, or a switch to a different propellant or some other minor thing.

[Grenny]

After reading the Kotsch website, I have to say I really don't understand how/why DM13A1 was produced when it's hardly better than DM13, and the DM23 looks like it's only a minor change from DM13 yet with much better penetration?

Modifications/new types don't allways mean improved penetration. They are also other parameters: accuracy, storage issues, temperature stability, burn time of tracers, tracer types ...etc etc etc

All kind of little things to make the round more useful :-)

[Tjay]

LOL, nice one Tjay.

Actually it's more for scenario design. I'm trying to create a scenario with T-80U and T-72Bs using the BM-32 and BM-42 ammo, as I understand these are more common rounds, but need to get an idea of how fast the rounds penetration falls off around 2km. The site Dejawolf came up with is a really good reference for that.

But now I'm faced with the same problem with M1's and Leopard 2's. I'm trying to set up so the usual range of engagement happens at 2km, and I don't want to give them a round that's too weak at 2km, but one thats not too powerful either.

Sort of forcing the player to use more maneuver instead of being able to blast them head on without thinking about armor protection.

Simulated ammunition in SB certainly seems to vary A LOT. Especially in older scenarios. To such an extent that some are regarded by more experienced players as unreasonably one-sided unless the ammunition specification is changed from the original.

[Ssnake]

Well, the ammo performance varies a lot because, well, there was tremendous advance in this field over the past four decades. Second, not every hit is a guaranteed kill as a lot of effort was put into making tanks more robus in post-penetration scenarios, with the M1 being an example of relatively high survivability - and the T-72 being close to the other end of the spectrum. Finally, the relatively high spatial resolution of the SB Pro vulnerability models means that there are spots which are pretty vulnerable, and other areas that hold up well under fire.

It is important to understand that basic stats like "frontal protection 730mm" or "penetration 680mm @ 1,500m" are just that - BASIC, simplified guidelines. Steel Beasts Pro is much more detailed than that, though it does NOT claim that the model has been validated and verified.

[Invader ZIM]

Out of curiosity, is it possible for the Leopard 2 series to fire the M829A3 round? Or is there a difference in the cannons, or the shells themselves that precludes it's use?

[Gibsonm]

Probably, since the US bought the German gun when they upgraded their M1s from 105mm (with a British gun) to 120mm.

So the physical weapons are probably compatible.

[Tjay]

Well, the ammo performance varies a lot because, well, there was tremendous advance in this field over the past four decades. Second, not every hit is a guaranteed kill as a lot of effort was put into making tanks more robus in post-penetration scenarios, with the M1 being an example of relatively high survivability - and the T-72 being close to the other end of the spectrum. Finally, the relatively high spatial resolution of the SB Pro vulnerability models means that there are spots which are pretty vulnerable, and other areas that hold up well under fire.

It is important to understand that basic stats like "frontal protection 730mm" or "penetration 680mm @ 1,500m" are just that - BASIC, simplified guidelines. Steel Beasts Pro is much more detailed than that, though it does NOT claim that the model has been validated and verified.

Thanks for the information. On reflection, I think the comment about having to change the ammo for a particular scenario to be evenly balanced was because that particular version gave the early Tx more modern ammunition, while Blue was restricted to the historically correct rounds.

Probably Marko's fault. We always blame Marko if there is a problem with Soviet equipment in ANY scenario.