Jagdtiger with 8.8cm Pak 43 L/71?

[Christian Ankerstjerne]

Okay, probably poor memory then - the table linked to above is very old, and I don't have access to my books.

[Tratt]

Munch's book has this photo on page 523, I must say that looks like a 12.8cm cannon on the Jagdtiger:

[Michi]

Hi!
Any penetration data for the 12.8cm Pak 80 (44) L/55?

128mm L/55 APC:
100m----282mm---189mm
250m----270mm
500m----251mm---166mm
750m----233mm
1000m---217mm---143mm
1500m---187mm---127mm
2000m---162mm---117mm
3000m---121mm


128mm L/55 APCBC:
100m----267mm---187mm
250m----262mm
500m----253mm---178mm
1000m---237mm---167mm
1500m---222mm---157mm
2000m---208mm---148mm
3000m---182mm


Sources:
Lorrin Bird's WWII Ballisics. (mm datas in the first row)
Chamberlain & Doyle. (mm datas in the second row)


The penetration datas for Panzergranate of the 12,8 cm Flak 40 seem to be 10-15% higher.



MfG Michi

[cbo]

Well, the Pzgr. 43 was actually APCBC-HE, similar to Pzgr. 39. It was a 28,3 kg shell with a 550 gram explosive filler.

I'm pretty sure the "PzGr." is the same round that was fired by the 12,8cm K40 used in the Pz Sfl V based on the VK3001(H) chassis of which two were made in 1942. AFAIK it was an APC round with no ballistic cap. As listed in Chamberlain & Doyle: "Encyclopedia..." the PzGr for the 12,8cm K40 and the PaK 44/PjK 80 are the same weight, the K40 achieving slightly better penetration by virtue of a slightly higher muzzle velocity, apparently.
The PzGr. 43 was slightly heavier and fired at a lower velocity and performed about the same as the PzGr at short range, the ballistic cap kicking in with range resulting in considerably better long range performance.
The many different penetration figures available for the PzGr 43 may have to do with different conditions (yards/meters, angle, British/US/USSR/German tests etc.). However, I seem to recall that the 12,8cm firing PzGr 43 was tested at different muzzle velocities achieving, obviously, different penetrations. They ended up using the lower velocity of 845 m/s quoted by Christian. IIRC the other velocties were 920 m/s and 1000 m/s. Firing the shell at the lower velocity may suggest that there was some kind of design or construction issue at play. I recall it being suggested the the big rounds tended to break apart on impact at the higher velocities. All this being from memory, of course.

As for the 128mm penetrating less than the 88mm, that is not necessarily against the laws of physics. There is the issue of weight and velocity but penetration depends on numerous other factors like shell design, materials, ballistics etc.

Anyway, here's some penetration figures from different sources, all 30 degree impact:

M/v 845 (Chamberlain & Doyle)
500m = 178
1000m = 167

M/v 920 (Senger und Etterlin)
500m = 215
1000m = 202

M/v 1000 (Hogg)
1000m = 230

Claus B

[Michi]

I'm pretty sure the "PzGr." is the same round that was fired by the 12,8cm K40 used in the Pz Sfl V based on the VK3001(H) chassis of which two were made in 1942.

Claus B

This can't be correct, as the 12,8cm FlaK 40 & FlaK 45 used one-piece grenades.
The 12,8cm PaK 44 & PjK 80 (a.s.o. ..) used two-pieces grenades.

MfG Michi

[LV]

I'm pretty sure the "PzGr." is the same round that was fired by the 12,8cm K40 used in the Pz Sfl V based on the VK3001(H) chassis of which two were made in 1942.

Claus B

This can't be correct, as the 12,8cm FlaK 40 & FlaK 45 used one-piece grenades.
The 12,8cm PaK 44 & PjK 80 (a.s.o. ..) used two-pieces grenades.

MfG Michi

Maybe the shell was the same even if the complete round was fixed in the other and separate-loading in the other.

If there was a round called simply "Pzgr." it would be my guess that it was originally ontended for use in the 128 mm AA guns. The 88 Flak guns also had a round called "Pzgr." which had a larger explosive filler (appr. 140g) than the Pzgr. 39 (appr. 55g) that was later used in KwK 36.

However, it must not be forgotten that the WZF 2/1 sight used in the Jagdtiger had only two range scales: one for AP shells and the other for HE shells. This, in my opinion, leads to the conclusion that there could not have been different AP shells since their flight trajectories would be different, thus rendering proper aiming very challenging indeed.

[Michi]

Maybe the shell was the same even if the complete round was fixed in the other and separate-loading in the other.

If there was a round called simply "Pzgr." it would be my guess that it was originally ontended for use in the 128 mm AA guns. The 88 Flak guns also had a round called "Pzgr." which had a larger explosive filler (appr. 140g) than the Pzgr. 39 (appr. 55g) that was later used in KwK 36.

Nevertheless it was not interchangeable within these two different 12,8cm guns.
It doesn't help you if the round has the same name, but it's different.
There was also a naval 12,8cm gun; and I'm pretty sure there was also a PzGr. (also not interchangeable with the others)



MfG Michi


PS:
I'm not sure in which forum, but I did it: I wrote down all 8,8cm guns (naval, anti-tank, anti-air, tank-gun, ....) (L/30, L/45, L/56, L/71, L/81 .....)
There were also some grenades with the same term, but you could not use it in the other gun!
some 25 or 27 different guns with 88mm
more than 100 different grenades.

[cbo]

I'm pretty sure the "PzGr." is the same round that was fired by the 12,8cm K40 used in the Pz Sfl V based on the VK3001(H) chassis of which two were made in 1942.

Claus B

This can't be correct, as the 12,8cm FlaK 40 & FlaK 45 used one-piece grenades.
The 12,8cm PaK 44 & PjK 80 (a.s.o. ..) used two-pieces grenades.

MfG Michi

I'm not talking about the FlaK 40 or Flak 45. I'm taling about the K40 in the PzSfl V. And that gun used separate loading ammunition. Not that it necessarily matters, the projectile could still be the same as the one used in the FlaK guns.

I' be curious as to what differences you think that there were between the projectile used by the K40 and PaK 44 and the Flak guns that prevented them from being used interchangably?

Claus B

[Michi]

I' be curious as to what differences you think that there were between the projectile used by the K40 and PaK 44 and the Flak guns that prevented them from being used interchangably?

Claus B

With the following specifications you can see why the different patron/cartridge(12,8cm FlaK) and grenades (12,7cm S.K. & 12,8cm PaK/KwK) are not interchangeable!

Here are my datas concerning some 12,8cm guns:

_________________________12,7 cm S.K. C/34 L/45____________12,8 cm FlaK 40 L/61________________12,8 cm PaK 80 L/55
Granatenart:___________________SprGr kz___________SprGrPatr L/4,5__PzGrPatr__PzGrPatr 43________SprGr L/5,0___PzGr 43
Geschoßlänge:_________________565 mm______________576 mm_______384 mm____478 mm____________623 mm____497 mm
Kartuschen-/Hülsenlänge:________732 mm______________962 mm_______962 mm____962 mm____________870 mm____870 mm
Gesamtlänge/Patronenlänge:__________________________1487 mm______1277 mm_____________________________
Geschoßgewicht:________________28 kg________________26 kg________26,35 kg____28,3 kg_____________28 kg_____28,3 kg
Kartuschen-/Hülsengewicht:_______16 kg__________________________________________________________11,6 kg____11,6 kg
Gesamtgewicht/Patronengewicht:_______________________48 kg_________46,5 kg___50,5 kg/48 kg
.............................................................................................................................Messing/Stahlhülsen
Geschoßanfangsgeschwindigkeit:___830 m/s_____________880 m/s_______950m/s_____980 m/s____________750 m/s____920 m/s

Sources:
Different original German data sheets from WWII.

Other datas are available, but not necessary.




MfG Michi

NB:
And yes, the 12,7cm S.K. has in reality a 12,8cm bore.

[cbo]

With the following specifications you can see why the different patron/cartridge(12,8cm FlaK) and grenades (12,7cm S.K. & 12,8cm PaK/KwK) are not interchangeable!

Here are my datas concerning some 12,8cm guns:

_________________________12,7 cm S.K. C/34 L/45____________12,8 cm FlaK 40 L/61________________12,8 cm PaK 80 L/55
Granatenart:___________________SprGr kz___________SprGrPatr L/4,5__PzGrPatr__PzGrPatr 43________SprGr L/5,0___PzGr 43
Geschoßlänge:_________________565 mm______________576 mm_______384 mm____478 mm____________623 mm____497 mm
Kartuschen-/Hülsenlänge:________732 mm______________962 mm_______962 mm____962 mm____________870 mm____870 mm
Gesamtlänge/Patronenlänge:__________________________1487 mm______1277 mm_____________________________
Geschoßgewicht:________________28 kg________________26 kg________26,35 kg____28,3 kg_____________28 kg_____28,3 kg
Kartuschen-/Hülsengewicht:_______16 kg__________________________________________________________11,6 kg____11,6 kg
Gesamtgewicht/Patronengewicht:_______________________48 kg_________46,5 kg___50,5 kg/48 kg
.............................................................................................................................Messing/Stahlhülsen
Geschoßanfangsgeschwindigkeit:___830 m/s_____________880 m/s_______950m/s_____980 m/s____________750 m/s____920 m/s

Sources:
Different original German data sheets from WWII.

Other datas are available, but not necessary.

MfG Michi

NB:
And yes, the 12,7cm S.K. has in reality a 12,8cm bore.

I fail to see you point? There is nothing in the data you posted for the 12,8cm FlaK 40 L/61 PzGrPatr projectile that would prevent it from being fired from the 12,8cm PaK 80.

Claus B

[Michi]

I fail to see you point? There is nothing in the data you posted for the 12,8cm FlaK 40 L/61 PzGrPatr projectile that would prevent it from being fired from the 12,8cm PaK 80.

Claus B

BECAUSE THE PROJECTILE OF THE FLAK WAS NEVER AVAILABLE, AS FOR ITSELF ALONE!!
FLAK USED A ONE-PIECE (THEREFORE THE GERMAN TERM: Granatpatrone)
PAK USED A TWO-PIECE (THEREFORE THE GERMAN TERM: Granate)

AND I FOR MYSELF SEE ANOTHER DIFFENCE; HAVE A LOOK AT THE:

Geschoßlänge (= projectile)



MfG Michi

[cbo]

Claus B

BECAUSE THE PROJECTILE OF THE FLAK WAS NEVER AVAILABLE, AS FOR ITSELF ALONE!!
FLAK USED A ONE-PIECE (THEREFORE THE GERMAN TERM: Granatpatrone)
PAK USED A TWO-PIECE (THEREFORE THE GERMAN TERM: Granate)

AND I FOR MYSELF SEE ANOTHER DIFFENCE; HAVE A LOOK AT THE:

Geschoßlänge (= projectile)

Stop shouting.

Projectile length doesn't mean anything. As you can see from your own data, the same gun could fire different length projectiles without problem.

Also, you seem to continue to ignore or fail to understand that the issue here is NOT the FlaK 40 ammunition. The 12,8cm K40 (that is Kanone, not FlaK) used in the Sfl V fired separate loading ammunition just like the 12,8 cm PaK 80 and it fired a PzGr. weighing 26.4 kg just like the PzGr that was allegedly fired by the 12,8cm PaK 80.

Another issue is, that this particular 12,8cm PzGr is very close in weight to the PzGr fired by the 12,8cm FlaK 40 (quoted as 26.5kg by Hogg and 26.35 by your source).

I really fail to see why it would be so difficult to use the FlaK 40 projectile in either the K40 or PaK 80. You could just take them from the production line before you mount them in the cartridge and issue them with the separate loading cartridge of the K40 or PaK 80. Hardly rocket science.....

Incidentally, the ammunition listed by Hogg for the 12,8cm K44 - that is the PaK 80 mounted in a towed field carriage - includes a 26kg 12,8cm SprGr FlaK 40. That is the HE shell for the 12,8cm FlaK which was used with the separate loading cartridge of the K44. He also mentioned examples of the HE shell for the K44, which carried naval acceptance stamps as well as having some grooves at the bottom indicating that they had started life as a fixed round and having the same driving band configuration as the HE rounds for the FlaK 40, basically indicating that the same HE shell could be fired by the FlaK 40, the K44 and the 12,8cm naval gun.

Of course, it wouldn't be the first time Hogg got things wrong, but if you want to argue that the K40 projectile or the FlaK 40 projectile could not be fired from the PaK 80, you need to find some valid reason in the projectile design itself.

Claus B

[Timber]

Well, the Pzgr. 43 was actually APCBC-HE, similar to Pzgr. 39. It was a 28,3 kg shell with a 550 gram explosive filler.

I'm pretty sure the "PzGr." is the same round that was fired by the 12,8cm K40 used in the Pz Sfl V based on the VK3001(H) chassis of which two were made in 1942. AFAIK it was an APC round with no ballistic cap. As listed in Chamberlain & Doyle: "Encyclopedia..." the PzGr for the 12,8cm K40 and the PaK 44/PjK 80 are the same weight, the K40 achieving slightly better penetration by virtue of a slightly higher muzzle velocity, apparently.
The PzGr. 43 was slightly heavier and fired at a lower velocity and performed about the same as the PzGr at short range, the ballistic cap kicking in with range resulting in considerably better long range performance.
The many different penetration figures available for the PzGr 43 may have to do with different conditions (yards/meters, angle, British/US/USSR/German tests etc.). However, I seem to recall that the 12,8cm firing PzGr 43 was tested at different muzzle velocities achieving, obviously, different penetrations. They ended up using the lower velocity of 845 m/s quoted by Christian. IIRC the other velocties were 920 m/s and 1000 m/s. Firing the shell at the lower velocity may suggest that there was some kind of design or construction issue at play. I recall it being suggested the the big rounds tended to break apart on impact at the higher velocities. All this being from memory, of course.

As for the 128mm penetrating less than the 88mm, that is not necessarily against the laws of physics. There is the issue of weight and velocity but penetration depends on numerous other factors like shell design, materials, ballistics etc.

Anyway, here's some penetration figures from different sources, all 30 degree impact:

M/v 845 (Chamberlain & Doyle)
500m = 178
1000m = 167

M/v 920 (Senger und Etterlin)
500m = 215
1000m = 202

M/v 1000 (Hogg)
1000m = 230

Claus B

A good and simple way to find out which gun itself has the highest armor penetration potential, if all esle is equal, is to divide KE with projectile surface area - in this case the 88mm Pak43 L/71 should be slightly ahead of the 128mm Pak44 IIRC.

The 128mm round is still better against armor sloped past 35 degree's from vertical though...

[LV]

On the ammunition used. The Datenblatt of 12,8 cm Pak 80 lists three different projectiles: 12,8 cm Pzgr. 43, 12,8 cm Sprgr. Flak 40 and 12,8 cm Sprgr. L/5,0.

The projectile weights are the following, respectively: 28,3 kg, 26,0 kg and 28,0 kg.

Muzzle velocities are stated to be 950 m/s (Pzgr.) and 750 m/s (Sprgr.).

Penetration is quoted as: 500 m: 219 mm, 1000 m: 200 mm and 1500 m: 187 mm. These are most likely against a plate at 60 degrees from horizontal (Anglo-American practise), or in other words, 30 degrees from vertical (Continental practise). Like on most other German documents as well, the penetration data is given at 30 deg. from vertical, unless stated otherwise.

This would prove that the gun had more penetrative power than any other antitank gun of WW II.