Why KV has "very low" chance at 90 meters to PzIII?

[killmore]

Please help me - why is this so?

Stats say that 76mm can penetrate 80mm at 30 degrees.

PzIII hull is only 70mm and not at 30 degrees to me - so why are chances so low???

Why is the chance to kill PzIV higher - it has more armour (and yes it is at 30 meters)

Was the 76mm gun really so wimpy?

[ September 04, 2002, 01:18 AM: Message edited by: killmore ]

[Chad Harrison]

Originally posted by killmore:

Please help me - why is this so?

Stats say that 76mm can penetrate 80mm at 30 degrees.

PzIII hull is only 70mm and not at 30 degrees to me - so why are chances so low???

Why is the chance to kill PzIV higher - it has more armour (and yes it is at 30 meters)

Was the 76mm gun really so wimpy?

IIRC, the early war 76mm gun was not all that spectacular. It was quite shorter when compared to the later modeles, and the AP ammunition was much more inferior than the germans ammo IIRC. In squad leader, the russian 76mm gun performed considerably worse than the american 76mm gun, even less than the american sherman 75mm gun! So if that helps . . .

Chad

[Grisha]

Here's your answer, killmore. You can thank my old bud, Jeff Duquette, for this as it is verbatim from his email to me

Regarding the MkIII and MkIV Panzers...

Additional 30mm face hardened, bolt on plates, were added to the MkIVG hull. These were added to both the drivers plate as well as the upper hull plates. So amour in these located was 50mm base plate plus a 30mm bolt on FH plate. The MkIVH was actually constructed with a homogeneous 80mm plate in both of these locations. Both of these location make up about 80% of the exposed face of the front portion of the MkIV...so must hull hits would impact either of these reinforced areas.

The MkIVF2 (the first MkIV equipped with the long 75mmL48 gun) didn't have the extra bolt-on plates or the uniform 80mm plate...so the drivers plate and upper hull plates were still only 50mm of face hardened armor at both the driver plate and upper hull plate areas.

Of interest to note is that while the MkIIIL and MkIIIM both had an addition 20mm plate bolted onto their turret mantlets giving them a thickness of 50mm base plus 20mm bolt on (total = 70mm) none of the latter model MkIV's (F, G, or H series) had this extra mantlet plate ala the late model MkIII's. So the late model MkIV's have a mantlet thickness of only 50mm.

Apparently the weight of the new 75mmL48 main-gun that was shoe-horned into the late model MkIV's turret resulted in the front suspension of the Panzer being over-loaded. Because of the weight of the main-gun an additional mantle plate could not be added to the MkIVF,G, or H. In other words the lowly MkIIIL & M are actually better armored frontally than the MkIVF, G or H.

[Bastables]

Originally posted by killmore:

Please help me - why is this so?

Stats say that 76mm can penetrate 80mm at 30 degrees.

PzIII hull is only 70mm and not at 30 degrees to me - so why are chances so low???

Why is the chance to kill PzIV higher - it has more armour (and yes it is at 30 meters)

Was the 76mm gun really so wimpy?

]

Because your 7,62cm guns are firing AP shells that are supposed to explode after penetrating armour. So the 7,62cm shell punches through 2cm of FH armour and the shell decides to explode in the dead space, we now no longer have a solid mass and it comes in contact with another 5cm FH plate with most of its velocity lost though the HE exploding and digging its way through 2cm of FH armour. The thicker armour on the PIV is just one solid plate, which presents comparably fewer difficulties to the 7,62cm gun.

Don't need tthose images.

[ September 04, 2002, 01:15 AM: Message edited by: Bastables ]

[killmore]

Originally posted by Bastables:

Because your 7,62cm guns are firing AP shells that are supposed to explode after penetrating armour. So the 7,62cm shell punches through 2cm of FH armour and the shell decides to explode in the dead space, we now no longer have a solid mass and it comes in contact with another 5cm FH plate with most of its velocity lost though the HE exploding and digging its way through 2cm of FH armour. The thicker armour on the PIV is just one solid plate, which presents comparably fewer difficulties to the 7,62cm gun.

Don't need tthose images.[/QB]

I updated the image links...

Wow - and CMBB simulates this?

I just found it incredible that PzII cannot be penetrated at 90 meters...

How did soviets ever survived 1943???

[Kwazydog]

Sure does killmore, along with a whole host of other stuff. Also, not that you arent quite shooting at the armour directly on (it looks like you are to the slight many maybe slightly below). This can also make a different.

Thats why we've said that nothing can come close to CMBB's armour calculations for a long time to come One day Charles will have to write a detailed explaination of just what is taken into account.

Dan

[K_Tiger]

Side angle is in the calculation?? wow...the best i read so far...so will tank crews use this and not place their vehicles with point blank to the ennemy??

[Chad Harrison]

Originally posted by K_Tiger:

Side angle is in the calculation?? wow...the best i read so far...

You bet it is. Shooting at a Tiger I at an angle in CMBO is your worst nightmare! Very true to life from a geometric point of view, and good to see attention to such a big factor like the angle towards to armor! You always want shots that hit the armor right on, not at an angle.

Chad

[killmore]

Actually angle looks much larger on this picture than it really was (less than 30 degrees)

KV cannot penetrate PzIII under 100m - you learn something new every day...

What was the point of making SU-76 then if they could not penetrate anything? Just as an infantry support?

Do soviets get getter ammo later in the war?

(I seem to recall they had Hollow-point for 76mm at the end of the war)

[killmore]

I also read multiple times that to Germans suprise Soviet 76mm was able to get penetration at point blank ranges on front of Tiger and Panter...

That seems impossible in CMBB

[Grisha]

What was the point of making SU-76 then if they could not penetrate anything? Just as an infantry support?

Yes, killmore, SU-76 was meant as infantry support, not something you wanted to use in tank vs tank encounters. The SU-85 and SU-100 were tank hunters, while the SU-76, SU/ISU-122, and SU/ISU-152 were primarily infantry support.

[Kwazydog]

Which 76mm killmore....the Russians had many?

Dan

[Mattias]

Originally posted by KwazyDog:

Which 76mm killmore....the Russians had many?

Indeed. The reference probably relates to the L/51.5 version that was captured and put to use by the Germans themselves (Pak36 r). The gun mounted on the T-34's and KV's was not as effective.

M.

[Guest Mike]

The bursting charge of hte APHE isn't so important - but hte Russians used blunt nosed AP shells.

These gave better performance against slopped armour than sharp nosed shells, but were worse against armour they hit flat on - IIRC you'll see "flat nose" or something similar in hte info screen for the tanks.

The standard Russian 76mm by 1943 was roughly comparable to the American 75mm in the Sherman. None of the early war short versions mounted on T34's would have existed by then - only 400 were made (T34's with the shorter L11 gun), and they had a distinctive mantlet shape and weak front turret armour.

[Panzer76]

Wow, what can I say, Im impressed!! Yes, please ask Charles to give us all an explenation on what goes on in the calculations, I wouldnt have belived this attentio to detail was modeled!

[Stoffel]

Hi Mattias,

these captured guns were the M1936 and they were rebored to allow usage of the standard german 75mm AP ammo

it had a lower velocity than the Pak 40 and was heavier than the Pak 40,was renamed 7.62mmpak36®

another gun was the 7.62 mm M1941/SiS field gun

this was a rare weapon though and in german service renamed as 7.62cm FK288/1®

[Silvio Manuel]

Originally posted by Chad Harrison:

</font><blockquote>quote:</font><hr />Originally posted by K_Tiger:

Side angle is in the calculation?? wow...the best i read so far...

You bet it is. Shooting at a Tiger I at an angle in CMBO is your worst nightmare! Very true to life from a geometric point of view, and good to see attention to such a big factor like the angle towards to armor! You always want shots that hit the armor right on, not at an angle.

Chad</font>

[TSword]

Killmore,

BST, P3M can be killed out at over 500m but not front on. We are in the third year of the campaign and your UberKV has now become a hopeless vehicle (stupidly heavy with a puny gun)....so suck it down.

P3M has spaced armor for upper Hullfront and turret mantlet. 20 mm Facehardenend plate around 15 cm in front of a 30 mm Facehardenend plate, think this makes it harder for AP at angle

Greets

Daniel

[ September 04, 2002, 04:56 AM: Message edited by: TSword ]

[Bastables]

Originally posted by Mike:

The bursting charge of hte APHE isn't so important - but hte Russians used blunt nosed AP shells.

These gave better performance against slopped armour than sharp nosed shells, but were worse against armour they hit flat on - IIRC you'll see "flat nose" or something similar in hte info screen for the tanks.

So how do you explain the fact that AP shells were less effective vs spaced vertical armour than equivalent single thickness vertical armour.

[Fetchez la Vache]

Originally posted by KwazyDog:

One day Charles will have to write a detailed explaination of just what is taken into account.

Noooooo! Then what would we be left with to argue about in the forums? Bren tripods probably...

[Bastables]

Originally posted by Fetchez la Vache:

</font><blockquote>quote:</font><hr />Originally posted by KwazyDog:

One day Charles will have to write a detailed explaination of just what is taken into account.

Noooooo! Then what would we be left with to argue about in the forums? Bren tripods probably... </font>

[Aacooper]

I suspect, but don't know, that the MkIIIM wasn't the most common variety of MkIII. So the 76mm-armed KV & T-34 had better luck against most '41-'43 German armor.

Does anyone have the model quantities at their fingertips?

[kevsharr]

Originally posted by Grisha:

</font><blockquote>quote:</font><hr />What was the point of making SU-76 then if they could not penetrate anything? Just as an infantry support?

Yes, killmore, SU-76 was meant as infantry support, not something you wanted to use in tank vs tank encounters. The SU-85 and SU-100 were tank hunters, while the SU-76, SU/ISU-122, and SU/ISU-152 were primarily infantry support.</font>

[Bastables]

Originally posted by Aacooper:

I suspect, but don't know, that the MkIIIM wasn't the most common variety of MkIII. So the 76mm-armed KV & T-34 had better luck against most '41-'43 German armor.

Does anyone have the model quantities at their fingertips?

You'd also have to include PIII ausf J with the KwK 38 5cm L/60 since the spaced armour was introduced at the same time as the longer gun.

(Some ausf J did enter combat with the longer 5cm gun yet sans spaced armour)

The entire ausf L line plus the ausf M. And of course all the older PIIIs remanufactured to the better specs.

[Lindan]

Originally posted by Bastables:

</font><blockquote>quote:</font><hr />Originally posted by Mike:

The bursting charge of hte APHE isn't so important - but hte Russians used blunt nosed AP shells.

These gave better performance against slopped armour than sharp nosed shells, but were worse against armour they hit flat on - IIRC you'll see "flat nose" or something similar in hte info screen for the tanks.

So how do you explain the fact that AP shells were less effective vs spaced vertical armour than equivalent single thickness vertical armour.</font>