German OOB 16: minor corrections

[Mario_Fr]

In the german OOB weapon 130 and 131 are named Steilgranate 41 and 42; it should be Stielgranate 41 and 42.

Weapons 207 - 209 are named BKannon or BordKannon.
I don`t mind if the names are given in english or german but Kannon is just weird. It should be Bordkanone or abbreviated BK.

All those Marder SPG`s that now have the StuK 40 should have the Pak 40 instead (the StuK was only mounted in the StuG III and IV).
And actually the Pak 40 should have slightly better penetration data than the KwK 40 / StuK 40, because of a larger cartridge case.

data from: (http://www.tarrif.net/cgi/production...ration_adv.php)
confer also WW2 Ballistics: Armor and Gunnery by Lorrin Rexford Bird and Robert Livingston page 61

KwK 40 / StuK 40 - 740m/s (vs. RHA plate @ 30°)

(PzGr. 39 APCBC)
100m - 99mm
500m - 91mm
1000m - 81mm
1500m - 72mm
2000m - 63mm

(PzGr. 40 APCR)
100m - 126
500m - 108
1000m - 87


Pak 40 - 790m/s

(PzGr. 39 APCBC);
100m - 106mm
500m - 96mm
1000m - 85mm
1500m - 74mm
2000m - 64mm

(PzGr. 40 APCR)
100m - 143
500m - 127
1000m - 97
1500m - 77



Unit number 376 (Tiger tank) has a front turret armour of 16. ALl the other Tigers have 12. I`m not a Tiger specialist but I didn`t knew that they increased the armour during production, but maybe I`m wrong.

Mario

[AMX]

Originally Posted by Mario_Fr

And actually the Pak 40 should have slightly better penetration data than the KwK 40 / StuK 40, because of a larger cartridge case.

Careful there - the KwK/StuK case was shorter, but fatter; the basic idea was to get the exact same performance in a package that fit in the turret of the Pz IV.
That didn't quite work out, supposedly due to extraction problems caused by overpressure.
But note that data for the PaK 40 is also inconsistent, with late war tests generally showing worse performance for no adequately explained reason.

Unit number 376 (Tiger tank) has a front turret armour of 16. ALl the other Tigers have 12. I`m not a Tiger specialist but I didn`t knew that they increased the armour during production, but maybe I`m wrong.

Not sure about armor thickness as a whole, but I know late production used a monocular instead of a binocular gunsight (thus one less hole in the armor) and reinforced the armor around it.

[DRG]

Originally Posted by AMX

Not sure about armor thickness as a whole, but I know late production used a monocular instead of a binocular gunsight (thus one less hole in the armor) and reinforced the armor around it.

That unit has had that armour rating for as far back as I have OOB's and a MOBHack that will read them that old ( Dec 2002 ) and this is the first time it's been questioned. I don't have a definitive answer other than given the number of German detail freaks who have had issues with the OOB over the years ( including info/debates/arguments regrading German armour hardening techniques) that this one, on the Tiger of all vehicles, would have be wrong all these years is very long odds but now *I'M* curious so I'll see what I can find ( or what info others can dig up ) between now and next years upgrade.

That said the first three issues on this thread (Stielgranate / BKanone / Marder gun )have been corrected



Don

[Mario_Fr]

Originally Posted by DRG

That said the first three issues on this thread (Stielgranate / BKanone / Marder gun )have been corrected



Don

Sorry Don, maybe you have already corrected it, unit 956 and 957 (RSO with Pak 40) also have to be changed to Pak 40.

Mario

[Mobhack]

This tank-net thread has some info on the L46 and 48 velocities in amongst the L/70 etc discussions: http://208.84.116.223/forums/index.p...c=37158&page=5 at about post 92 on.

If you can make some sense of that (the figures are all over the place, and the charge seems also to have been de-rated in the later war), and then put some argument re the game figures from official documentation and so on and so forth then we may have a change. Otherwise things will likely remain the same.

Andy

[Mario_Fr]

Originally Posted by Mobhack

This tank-net thread has some info on the L46 and 48 velocities in amongst the L/70 etc discussions: http://208.84.116.223/forums/index.p...c=37158&page=5 at about post 92 on.

If you can make some sense of that (the figures are all over the place, and the charge seems also to have been de-rated in the later war), and then put some argument re the game figures from official documentation and so on and so forth then we may have a change. Otherwise things will likely remain the same.

Andy

Well, I`ve read the tank-net thread and you`re right, it`s quite confusing.
Before giving another figures and quoting sources (which is actually like opening a fight of numbers) I have to admit that my knowledge is based on one primary source (Wolfgang Fleischer, Gepanzerte Feuerkraft. Die deutschen Kampfwagen-, Panzerjäger- und Sturmkanonen, 2004), but tarrif.net and Rexford Bird / Livingston are confirming it.

In Fleischer`s book is a description of the two cartridge cases (100 x 716mm for the Pak 40 and 111,5 x 495,1mm for KwK 40 L43 and L48) and the weight of the propellant (2795g for Pak 40 and 2520g for KwK 40). Also there`s a picture showing the two cartidges side by side.

Looking at all the different numbers it seems that there are two different opinions.

First: KwK L43 and KwK L48 actually have the same pen-data using the same shell but Pak 40 has slightly better penetration (as stated by Fleischer, tarrif.net and Rexford Bird / Livingston (they even distinguish between the three of them but KwK L43 and L48 have only 2mm difference: KwK 40 L43-133mm; L48-135mm; Pak 40-146mm for 100m)

Second: no difference between KwK L48 and Pak 40 but KwK L43 has slightly less penetration (as it is in the game right now).

To be honest, I only knew the first opinion before, that Pak 40 has slightly better penetration. Official documentation is out of reach, but maybe someone can come up with it.

Mario

[Cross]

Originally Posted by Mario_Fr

Looking at all the different numbers it seems that there are two different opinions.

First: KwK L43 and KwK L48 actually have the same pen-data using the same shell but Pak 40 has slightly better penetration (as stated by Fleischer, tarrif.net and Rexford Bird / Livingston (they even distinguish between the three of them but KwK L43 and L48 have only 2mm difference: KwK 40 L43-133mm; L48-135mm; Pak 40-146mm for 100m)

Second: no difference between KwK L48 and Pak 40 but KwK L43 has slightly less penetration (as it is in the game right now).

To be honest, I only knew the first opinion before, that Pak 40 has slightly better penetration. Official documentation is out of reach, but maybe someone can come up with it.

Mario

The info I have shows this:

APCBC at 1,000 yds 30deg

StuK 40.......72mm (US Army Tech Manual 1945)
KwK 40 L43....72mm (Bovington Tank Museum)
KwK 40 L48....79mm (Bovington Tank Museum)
PaK 40.......102mm (US Army Tech Manual 1945)

NB. The US Army tech manual says there was no change in ballistic characteristics of the KwK 40 L43 and L48.

My 'Bovington' doc. (a friend gave it to me and said it came from Bovington) No idea what book or publication.









Cross

[Mario_Fr]

But the sheet VII-58 also gives a penetration of 72mm for 1000 yards for the L48 (right column, topic remarks).

in: ... 945.StuK40.jpg

Mario

[cbo]

Everybody, his uncle and his sons dog have figures for these guns and you can quote from the now until the end of history without really solving the issue. The solution to the problem lies, unfortunately, in the primary sources, i.e. those produced in context with the firing test, calculations and estimations of performance. And as far as I know, no one have managed to find anything conclusive on the matter of the many different muzzle velocities registered for these guns.

I dont want to discourage discussion, that always turns up some interesting snippets of information, but the issue of muzzle velocity is complex (conditions of test, propellant used, age and condition of ammunition used etc.) and the issue of penetration on top of that much more so.

But as long as the differences between figures amounts to less than 10%, it hardly matters in game terms.

[DRG]

Originally Posted by Mario_Fr

Unit number 376 (Tiger tank) has a front turret armour of 16. All the other Tigers have 12. I`m not a Tiger specialist but I didn`t knew that they increased the armour during production, but maybe I`m wrong.

Mario

I'm glad you brought this up. I checked back and the OOB's have been this way for over a decade and you are correct, there were no turret armour upgrades for the Tiger I front turret aside for details that are trivial in game terms.

After a couple hours digging up info and emails exchanged on two continents factoring in the variations of mantle thickness with the actual turret front armour where it and the mantle overlap then averaging those values to arrive at one number we could use what was arrived at was the 1944 Tiger in the game has the correct armour value and the pre 1944 version only took into account average mantle thickness.

The bottom line is Unit #376 has the correct armour and unit #31 and #849 have now been corrected to match #376.

Congratulations......they had been like that for over 11 years and you were the first one to notice and comment.

Don