German 7,5cm gun question

[Mattias]

Originally posted by Claus B:

That sounds very reasonable. What makes me wonder though is that the test, according to Spielberger that is, was made with the KwK40, which we know by now is not the PaK40. Furthermore, the test also coincide with the time for the start of KwK40 production. But, as you say, why then would the Vo of the L/48 be much lower in practical use?

Not exactly to the point but still interesting is a note I found in Wolfgang Fleischers book "Die deutsche Panzerjägertruppe 1935-1945":

In the last year of the war great consideration was taken to the use of ammunition, especially to the economical use of the same.

Basically the PaK40 was to fire HL shots at all targets that did not absolutely require (zwingend notwendig) regular AP, this would be Pzgr. Patr. 39 as the "40" grenades were "hardly ever" available by 1944. What dictated this use was that the success must not be unduly compromised. For example, at very short range the reliability of the HL grenades was compromised by the high Vo of the PaK40 and at all ranges armoured vehicles with "Vorpanzer" (spaced armour) were hard or impossible to defeat.

The bottom line being that HL was to be the first choice for a PaK crew unless circumstances dictated otherwise.

M.

[illo]

I CAN*T PENETRATE SHERMAN FRONT HULL FROM 1200m WITHMY PZKPFW-IVH!!!!

THIS IS NOT CORRECT!!!!

BTS FIX OR DO SOMEFINK!!!!!!!! DO SOMEFINK!!!!!

[JasonC]

So if I am following you correctly, Claus B, Chamberlain and Ellis have essentially the same theory I proposed, but the other sources - the majority and most of the German ones - disagree. And the likely muzzle velocities achieved are essentially the same for the two lengths of the two KwKs (740 vs. 750), reflecting not barrel length but propellant charge, in turn dictated by recoil room on an AFV.

Then BTS would be on the money with the Pz IV penetration tables, but the StuGs should have the same, as low as the Pz IVs, not mid-way between them and the PAK 40s. (Assuming the same recoil issues and thus chamber size and propellant charge applied in the StuK 40). That is perfectly plausible, if a bit counterintuitive on the motivation for the change of type to the L48 (i.e. that is was not seeking additional AP energy, but ease of production).

It leads me to another question, then. Is the PAK 39 in the early Jagdpanzers equivalent to the PAK 40, or to the KwK and StuK 40s? Also, I have seen the gun in the Hetzer identified as a 75L48. Was it, or an L46 with the larger chamber? Note that in CM today, both of these vehicles have the higher penetration numbers of the towed PAK 40, and of the Marders, i.e. are modeled on 790 m/s muzzle velocity.

[Mattias]

Jason,

The length of the barrel is the only difference between the KwK40 L/43 and L/48. All differences in ballistics derive from this fact.

And yes,

There is no reason to differentiate between the weapons carried by the Pz IV's, the StuG's, the JgPz IV L/48 and the Hetzer. They should all have the same penetration table, somewhere in the current Pz IV - StuG range.

The increase in Vo in the L/48 gun was used because it was there for the taking.

And no, so far nothing has been shown that contradicts that..

The PaK39 was the same weapon as the KwK and StuK, sharing the same ballistic characteristics.

The open topped tank hunters and AT guns should all be using the same table, representing the PaK40, somewhere a few "millimeters" above the current level.

This judging not by Vo but rather by looking into John Salts penetration table compilation and the current discussion.

M.

[MajorBooBoo]

Originally posted by Mattias:

The length of the barrel is the only difference between the KwK40 L/43 and L/48. All differences in ballistics derive from this fact.

M.

No, the rifling twist is also different. I thought that was already discussed.

It would be interesting to know if the rifling in the L43 resulted in a greatr shell spin and accuracy. Some guns with progressive shell spin just start out slowly and increase to a normal spin. Others have a dramatic pitch increase.

[MajorBooBoo]

Originally posted by JasonC:

It leads me to another question, then. Is the PAK 39 in the early Jagdpanzers equivalent to the PAK 40, or to the KwK and StuK 40s? Also, I have seen the gun in the Hetzer identified as a 75L48. Was it, or an L46 with the larger chamber? Note that in CM today, both of these vehicles have the higher penetration numbers of the towed PAK 40, and of the Marders, i.e. are modeled on 790 m/s muzzle velocity.

Unless the PAK39 had some kind of progressive twist, I would say that it is the same as a Panzer IV, StugIII_late, L48s, etc.

I cant believe the germans would have a separate barrel type for this common weapon. I guess if someone could look down the barrel of a Hetzer or a JagdpanzerIV, they would know for sure.

A thread with JasonC in it and no Steve from BTS yet?

[Claus B]

Originally posted by Mattias:?

What makes me wonder though is that the test, according to Spielberger that is, was made with the KwK40, which we know by now is not the PaK40. Furthermore, the test also coincide with the time for the start of KwK40 production. But, as you say, why then would the Vo of the L/48 be much lower in practical use?

It is difficult to say, you can imagine all sorts of test rigs being used, perhaps one allowing for longer recoil. Also, it is not unlikely that the KwK 40 cartridge could hold more propellant than was actually used in the production versions.

Not exactly to the point but still interesting is a note I found in Wolfgang Fleischers book "Die deutsche Panzerjägertruppe 1935-1945":

In the last year of the war great consideration was taken to the use of ammunition, especially to the economical use of the same.

Basically the PaK40 was to fire HL shots at all targets that did not absolutely require (zwingend notwendig) regular AP, this would be Pzgr. Patr. 39 as the "40" grenades were "hardly ever" available by 1944. What dictated this use was that the success must not be unduly compromised. For example, at very short range the reliability of the HL grenades was compromised by the high Vo of the PaK40 and at all ranges armoured vehicles with "Vorpanzer" (spaced armour) were hard or impossible to defeat.

The bottom line being that HL was to be the first choice for a PaK crew unless circumstances dictated otherwise.

This is quite interesting because Gr.38 Hl/x appears to have been a rather unsuccesfull development. I dont recall ever reading a positive comment about it, it was not very accurate (low muzzle velocity), it took a large number of hits to guarantee a kill etc. Production ran from 1942 to 1943 and was then cut, a fact that would also suggest that is was not very succesfull.

Still, about 1.8 million rounds were produced and about 1.1 million fired. In 1943 Gr.38 Hl/x made up about 50% of the armour piercing ammunition fired by the PaK 40 and about 30% of total ammo expenditure, In 1944 the numbers are about 30% of AP and about 16% of the total. Possibly, this is the reason for the passage you mentioned from Fleischer - the Wehrmacht had a large stock of Gr.38 Hl/x that was not being used while at the same time they had to produce more PzGr 39 to satisfy demand.

Regarding the muzzle velocity, the Gr. 38/Hl was fired at 450 m/s, but in order to function properly, it was not to be used at short range. Possibly, the cone could collapse before the jet had formed properly?

Claus B

[ February 23, 2002, 07:16 AM: Message edited by: Claus B ]

[Claus B]

Originally posted by MajorBooBoo:

Unless the PAK39 had some kind of progressive twist, I would say that it is the same as a Panzer IV, StugIII_late, L48s, etc.

According to Spielberger, the rifling twist was the same for the PaK 39 as for the KwK 40 and I'm almost 100% shure that both had 32 grooves.

Claus B

[Claus B]

Originally posted by JasonC:

So if I am following you correctly, Claus B, Chamberlain and Ellis have essentially the same theory I proposed, but the other sources - the majority and most of the German ones - disagree.

I think it is too much to say that Chamberlain and Ellis have a "theory", they have just tabulated some numbers.

But it is of course possible that they have drawn the same conclusions you did, that the PaK L/46 was basically the same as the KwK L/48.

Originally posted by JasonC:

And the likely muzzle velocities achieved are essentially the same for the two lengths of the two KwKs (740 vs. 750), reflecting not barrel length but propellant charge, in turn dictated by recoil room on an AFV.

The KwK 40 L/43 = 740 and KwK 40 L/48 = 750 m/s is a guess on my part. I've seen 740 and 750 for both.

Originally posted by JasonC:

Then BTS would be on the money with the Pz IV penetration tables, but the StuGs should have the same, as low as the Pz IVs, not mid-way between them and the PAK 40s. (Assuming the same recoil issues and thus chamber size and propellant charge applied in the StuK 40). That is perfectly plausible, if a bit counterintuitive on the motivation for the change of type to the L48 (i.e. that is was not seeking additional AP energy, but ease of production).

There is really nothing to suggest that the StuK 40 should be any different from the KwK 40 in terms of performance in either the L/43 or L/48 version. In "Sturmgeschütze" Speilberger does give a 790 m/s muzzle velocity for the L/48, but there is nothing in other parameters given for the gun to suggest that it was 790 m/s. Its the same ammo, same barrel length etc. as the KwK 40. Possibly, Spielberger has taken the 790 m/s from the same or similar source used by Chamberlain and Ellis?

Claus B

[MajorBooBoo]

In regards to hollow charge:

German units were sometimes short of 75mm HE and the use of HC as a substitute was official. On the eastern front, battling ATGs required HE in most tank/assault gun loadouts. Dedicated Panzerjager units might have had more AP specific loadouts (ie AP39 and AP40 taking up much of the racks with a small number of HE and HC)

HC:

For attacking bunkers and hardened targets, it would probably be OK but it wouldnt be that useful against troops in the open. Its poor accuracy beyond 500-600 meters would require close in shooting.

The 75mm HC was marginal at best. More a defensive weapon for guns like the L24. The amount of space it took up (because multiple shots/hits were needed) did not make sense for the supply line or the ammo racks in the vehicles.

[Brian]

Originally posted by MajorBooBoo:

In regards to hollow charge:

German units were sometimes short of 75mm HE and the use of HC as a substitute was official. On the eastern front, battling ATGs required HE in most tank/assault gun loadouts. Dedicated Panzerjager units might have had more AP specific loadouts (ie AP39 and AP40 taking up much of the racks with a small number of HE and HC)

HC:

For attacking bunkers and hardened targets, it would probably be OK but it wouldnt be that useful against troops in the open. Its poor accuracy beyond 500-600 meters would require close in shooting.

The 75mm HC was marginal at best. More a defensive weapon for guns like the L24. The amount of space it took up (because multiple shots/hits were needed) did not make sense for the supply line or the ammo racks in the vehicles.

Why do you consider that it was "marginal at best", MBB?

[Brian]

Out of a matter of interest, does anybody have any information about the performance of the following 7.5cm rounds, beyond what is briefly mentioned in Hogg's "German Artillery of World War II"?

7.5cm Pzgr PAK Patr TS 42

7.5cm Sprgr 38 H1/C Klappleitwerk

Were either ever issued?

[MajorBooBoo]

Originally posted by Brian:

Why do you consider that it was "marginal at best", MBB?

Combat accounts report that it was inaccurate beyond 500-600 meters. This meant that the germans had to get within the effective range of the enemy weapons. These accounts also reiterate that it took multiple hits to get a destroyed target. Hard to get hits and multiple hits needed is not a formula for success.

If it could at least have a high percentage of destruction when it DID get a hit, then I would consider it mildly effective. But I consider it marginally effective at best.

It was really a defensive round for 75mmL24. It allowed them to have a chance of success. In longer 75mm weapons, its performance/effects did not warrent the amount of rounds that had to be fired. Its performnce at long range (penetration being largely range independant) was offset by the inability to hit at long range.

The troops didnt believe in it either, if that has any weight. The rarity of HE and the decree to use HC in its place means that the germans had to find a use for them.

[Mattias]

It definitely seems like the HL munitions used by the Germans were a far cry from the hyper effective HEAT rounds fielded today that reaches penetrations of almost ten times their own diameter.

But it also seem as the critical lack of standard AP and even HE at times force the gunners to load up with HL rounds. Worst afflicted were most likely the motZ PaK units but at times it seems the Panzers too had to make do with HL ammunition.

During the early war period when the 7.5 cm guns consisted mostly of L/24 weapons the HL ammunition was used, naturally, because it was the only type of ammunition likely to make an impression on the T34’s and KW’s.

--

I picked up a few pieces from different books that lends some anecdotal understanding of the use of HL ammunition for the 7.5 cm guns in question. In no particular order, freely

translated, and with only minor comments. If anything they show a lot of inconsistencies in the sources:

--

"Begleitwagen Panzerkampfwagen IV" by Spielberger & Co.

In February 1942 Hitler finally released the 7.5 cm Gr. Patrone 38 for use. This type of ammunition was actually ready for use in April 1941 but was withheld from the front in order to no alert the enemy of it. It was feared that the Soviet forces would copy it.

[This sounds extremely odd when one considers the critical need for effective AT weapons at the front in 1941 and the lack of German weapon systems that were impervious to standard AP.]

--

Panzer Regiment 203 reported that the T34 could be defeated with HL grenades from 150-800 meters if hit in the side between the 5th and 6 th roadwheel. The front could be penetrated from 150-400 meters if the glacis MG was hit. The armour of the KW could not be defeated by the HL/A (45mm @ 60 degrees (30 in CM)) though.

--

With KwK40 L/43 all tanks were defeated at 1200-1600 meters with only two or three shots, every hit causing catastrophic fire. With the HL/B ammunition the target was only rarely set on fire and one to five shots where required for a kill.

[Every shot causing catastrophic fire? My that sounds bad]

--

"Panzertruppen I & II", by Jentz

The East:

The T34 can be penetrated at ranges up to 1000 meters with the 7.5 cm KwK40 as well as with the 7.5 cm HL grenades (report from May 1942).

--

Penetrating effect of Gr.38 HL fired by 7.5 cm KwK L/24:

T34: 150-800 meters at hull between 5th and 6th roadwheel. 150-400 meters at the glacis machine gun ball mount.

KW-I: 150-600 meters at hull and turret side. 140-300 meters at hull front.

[sounds a lot like the report found in Spielbergers book above, except for the results achieved against KW’s]

--

Report from III. Abt. / Pz.Reg. 6 on KO’s achieved between 12th and 22d of may 1942:

5 KW rendered inoperable by 7.5 cmHL grenades and subsequently blown up. None of the HL grenades penetrated the armour.

24 T34 were knocked out by 7.5 cm HL grenades

2 Mark II (Matilda?) knocked out by 7.5 cm HL.

--

It required about eight HL grenades to set each of the KW-I on fire.

--

5th Pz. Div. reports in engagements between the 22 February to 20 March 1943.

7.5 cm KwK L/24:

1 KW-I, 6 T34, 1 T60, 4 T26, 1 Mark II, 4 Mark III, 1 Gen. Lee. Gr.38 HL/B has destructive effect when fired at ranges under 600 meters at the hull and rear of the KW-I. The T34 was also engaged by firing at the hull. Three to six rounds of Gr.38 HL/B were required to kill each enemy tank.

Gr.38 HL/B was seldom fired by the 7.5 cm KwK L/43 tanks. One to five rounds were reqiured to set an enemy tank on fire.

--

Panzer Abt. 116 reported that after fighting 76 battles and moving 3020 km between 1 July 1943 and 31 January 1944 They had expended the following amount of 7.5 cm ammunition:

KwK40 HE: 4867

KwK40 AP: 1798

KwK40 HL/B:1237

KwK L/24 AP:39

KwK L/24 HL/B: 99

--

(Italian front) Another Churchill was set on fire by a 7.5 mm L/24 firing six HL grenades.

--

--

"Die deutschen Sturmgeschütze 1935-1945" by Wolfgang Fleischer

From July 1940 the 7.5 cm Granatpatrone 38 was available. With this could 40 mm of armour be penetrated, independently of range. Thus the StuG had the chance to achieve occasional penetrations of the front and sides of the T34. The chance to damage a KW tank was even less.

[i don’t know what HL grenade this might refer to, as far as I have seen the HL/A was the first. But I assume there could have been an even earlier model.]

--

In the end of 1941 improved HL grenades were delivered. First came the HL/A, then the HL/B with, respectively, 70 and 75 mm penetration. Now the tank hunting could again be conducted under 1500 meters more successfully. Between four and six shots where still required to achieve a hit.

..

Because of its low velocity it was difficult to hit with the HL grenades. At 90 degrees the 38 HL/C grenades could achieve 90 mm penetration, a figure that sunk to 45mm against armour angled at 30 degrees (60 degrees in CM terms).

--

"Die deutschen Panzerjägertruppe 1935-1945" by Wolfgang Fleischer

(late war) As a rule HL ammunition shall be used unless the situation absolutely requires the use of regular AP. Prime examples of such circumstances are at short distances, due to the excessive force of impact, and when faced with heavily armoured targets.

---

Well, food for thought. I will be interesting to see how all this confusion can be translated into CM.

Unless the vehicular moral, the new extreme FOW level and new tank accuracy and bracketing formulas takes CM to another level of realism, it is pretty hard to imagining a single tank having the time to fire the required number of HL rounds at a target that can in turn destroy it fairly easily.

M.

[ February 23, 2002, 06:21 PM: Message edited by: Mattias ]

[M Hofbauer]

I am very interested in this PzGr 38 - discussion as I had been musing over the different versions and their introduction dates recently.

I want to contribute my findings so far and would be very happy for your comments and contributions that might help to clear up the matter.

Originally posted by Mattias:

From July 1940 the 7.5 cm Granatpatrone 38 was available. With this could 40 mm of armour be penetrated, independently of range. Thus the StuG had the chance to achieve occasional penetrations of the front and sides of the T34. The chance to damage a KW tank was even less.

[i don’t know what HL grenade this might refer to, as far as I have seen the HL/A was the first. But I assume there could have been an even earlier model.]

Mattias,

it seems to me there were actually *four* models of the 7,5cm-Granate 38:

PzGr 38,

PzGr 38 HL/A,

PzGr 38 HL/B and

PzGr 38 HL/C

this is what I concluded so far:

The original PzGr 38 introduced the shaped charge and was available in June 1940. The shaped charge weighed 4.5kg, Vo of 452m/s, armor penetration of 40mm independent of range, effective range 1,200m

In the latter part of 1941 the improved versions of the PzGr 38 were introduced, first the HL/A with a penetration of 70mm, then the HL/B with a penetration of 75mm.

As late as spring 1943 the HL/B was still the standard HC ammunition, indicating that the HL/C had not been introduced then.

The HL/C featured a further increased penetration capability which is cited between 90 and 100mm.

To be honest, what found most surprising in all this was that I had always thought that the Pz.Gr. 38 HL/A had been introduced by the outbreak of WW II, yet it seems not even the original Pz.Gr. 38 had been issued then.

WEhat do you think? Where do your findings so far contradict above data?

curious,

Markus

[Mattias]

Nothing as far as I can see Marcus. Those names, numbers and dates check out in the sources I have looked into. Actually I passed by you site earlier today to check if you had any info available, reluctant as I am to trust a man that still thinks schürtzen were mounted to counter HL weapons

I did find this list of Pz IV ammunition, including a cannister round I had no idea existed. Check it out, it is a fine site:

http://ourworld.compuserve.com/homepages/willphelps/Specs-03.htm

It seems to me that there ought to have been at least one book published on this subject...

Ah, well, bedtime. Good night.

M.

[ February 23, 2002, 07:09 PM: Message edited by: Mattias ]

[MajorBooBoo]

"Panzer Abt. 116 reported that after fighting 76 battles and moving 3020 km between 1 July 1943 and 31 January 1944 They had expended the following amount of 7.5 cm ammunition:

KwK40 HE: 4867

KwK40 AP: 1798

KwK40 HL/B:1237

KwK L/24 AP:39

KwK L/24 HL/B: 99"

The interesting thing is that HC is being used as much as it is. Another interesting thing is the HE being the majority expenditure.

To be fair, the unit only had a few PnzIII/75 during this period and at some times none at all (from October on). The few PnzIII/75 did use HC (HL/B) in greater numbers than ordinary AP though (which is logical).

The L48s used more AP than HC. The funny thing is no listing of HE for the short 75s! I would think thats what they were supposed to be used for? Perhaps there was a shortage of 75L24 HE? I wouldnt think so given the haltracks and armored cars also using these stumpy 75's?

This unit only had between 10 and 20 PnzIV 75L48 during this period. Most of the time, the PnzIIIL60 were the majority tank (up till Jan 1944?). They used:

5700 HE

2845 AP

Again showing the use of HE to AP (2:1). The unit's claims (always a touchy topic), show an equal amount of tanks to guns destroyed. The disproportionate use of HE to AP gives a general idea what it was like for tanks to do battle with the ATG's.

This is good east front stuff. This unit must have been operating in favorable conditions to enjoy such success.

But we are off topic and I wonder if the L48 vehicle dependant performance issue is going to be addressed?

[MajorBooBoo]

Originally posted by Mattias:

I did find this list of Pz IV ammunition, including a cannister round I had no idea existed. Check it out, it is a fine site:

http://ourworld.compuserve.com/homepages/willphelps/Specs-03.htm

It seems to me that there ought to have been at least one book published on this subject...

Ah, well, bedtime. Good night.

M.

Thats a great website! How did you find it?

An interesting thing from the website is:

Sprgr. 34

HE

60/40 Amatol

0.454 kg.

Zdlg. Np. 10

Kl. Az. 23umg

olive green

-

Sprgr. Kw. K. (34)

HE

60/40 Amatol

0.853 kg.

Zdlg. C/98

Kl. Az. 23

olive green

-

Many refs give the Spegr KWK (34) as teh 75mm HE. But what is this Mini-KWK34? Its payload is only one pound of explosive? Given the 75mm diameter and density of steel, it must have been some thick walled type of hybrid round? Perhaps to penetrate concrete or thick bunkers?

[ February 23, 2002, 07:31 PM: Message edited by: MajorBooBoo ]

[JasonC]

To Matthias - on the discrepancy in reports of 75mm HEAT against KVs, keep in mind that the KV came in several varieties.

The KV-1 A series of 1940 had 90mm turret front and 75mm on most other surfaces. The KV-1 B series of 1941 had additional armor welded or bolted on - 25-35mm. Then the KV-1 C of 1942 used cast armor up to 120mm on the turret, with 90mm on the hull - armored like a Tiger I, even allowing for some reduction in armor quality. The KV-1S (42-43) reduced the armor to 75mm again, though some still had added plates bolted on. The KV-85 (43, few made) had a thick turret but thinner hull armor. KV-1 models ranged from 42 to 48 tons with such variations - and I don't mean the KV-2.

I would not expect pre HL/C style 75mm HEAT to muss the hair of a KV1-C. But it is perfectly plausible that flat hits on KV1-A or KV1-S models by HL/B would have been more effective.

[Brian]

Originally posted by MajorBooBoo:

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

Why do you consider that it was "marginal at best", MBB?

Combat accounts report that it was inaccurate beyond 500-600 meters. This meant that the germans had to get within the effective range of the enemy weapons. These accounts also reiterate that it took multiple hits to get a destroyed target. Hard to get hits and multiple hits needed is not a formula for success.

If it could at least have a high percentage of destruction when it DID get a hit, then I would consider it mildly effective. But I consider it marginally effective at best.

</font>

[Bastables]

Originally posted by MajorBooBoo:

"Panzer Abt. 116 reported that after fighting 76 battles and moving 3020 km between 1 July 1943 and 31 January 1944 They had expended the following amount of 7.5 cm ammunition:

Again showing the use of HE to AP (2:1). The unit's claims (always a touchy topic), show an equal amount of tanks to guns destroyed. The disproportionate use of HE to AP gives a general idea what it was like for tanks to do battle with the ATG's.

Or that HE was not only used on enemy ATG's but also other soft targets like field kitchens.

[Mattias]

Originally posted by JasonC:

[QB]To Matthias - on the discrepancy in reports of 75mm HEAT against KVs, keep in mind that the KV came in several varieties.[QB]

I'm sorry Jason this comes from condensing the materiel too much...

In the first report, the one from "Begleitwagen Panzerkampfwagen IV" by Spielberger & Co., it is specifically stated that the - 75 mm armour of the KW-I withstood hits from the HL/A. Hence the discrepancy between the reports. Perhaps it is not the same report after all and that HL/B was used by the unit, apparently, succeeding against some KW's. There is not enough information in my books to form an absolute opinion.

--

As for the use of HE in relationship to that of AP, as Bastables points out, the former is used against every target on the battlefield that can't effectively be brought down with MG fire and does not absolutely require AP. And there are definitely more of those targets around than AFV's.

--

I think the thoughts that Brian put forth matches very well the impression I have been given so far with regards to the general feeling towards the HL rounds.

By the way, is anyone seeing an references claiming that 7.5 cm Pzgr. HL grenades were used in 1941 or earlier, contrary to the statement by Spielberger that they were "released" in 1942.

M.

[ February 24, 2002, 05:55 AM: Message edited by: Mattias ]

[Claus B]

Hofbauer is right, there were 4 different versions of the Gr.38

Gr.38 Hl

Gr.38 Hl/A

Gr.38 Hl/B

Gr.38 Hl/C

The different models are described by Hogg in "German Artillery of WWII" in the entry about the 10.5cm l.FH. Even though this was 105mm ammunition, I'm pretty shure that the basic design changes were the same across the board, including the 7,5cm for PaK 40, KwK 37 and KwK 40.

As for the dates of introduction, I've reached the following conclusion, so far:

Gr.38 Hl:

Introduced in June 1940. First combat use in North Africa early 1941 (Fleischer IIRC). Apparently withdrawn from service soon after. Still, some StuG units apparently used the Gr.38 Hl (unknown model) early in the Russian campaign. Maybe only the first batch of Gr. 38 Hl was withdrawn from service?

Gr. 38 Hl/A:

Introduced in early 1942 (maybe late 1941)

Gr. 38Hl/B:

This version is mentioned in reports dated March 1943, so it must have been in use by then.

Gr. 38 Hl/C:

A January 1944 report one ammo expenditure for PzAbt. 116 only mentions Hl/B, so Hl/C must have been introduced after this date, though production probably began in 1943. The gunnery manual for the Jagdpanzer IV and Hetzer (Merkblatt 47b/45) of June 1944 mentions both Hl/B and Hl/C.

As for the ammunition expenditure, the following data can be compiled from Hahn: "Waffen und Gehiemwaffen...":

1942:

PaK 40 - Total = 118,000

PaK 40 - PzGr 39 = 42,000

PaK 40 - PzGr 40 = 0 (only 7,700 produced)

PaK 40 - Gr.38 Hl/x = 13,000

PaK 40 - SprGr = 63,000

KwK 40 - no data

1943:

PaK 40 - Total = 1,250,000

PaK 40 - PzGr 39 = 359,000

PaK 40 - PzGr 40 = 42,000

PaK 40 - Gr.38 Hl/x = 374,000

PaK 40 - SprGr = 476,000

KwK 40 - Total = 2,167,000

KwK 40 - PzGr 39 = 499,000

KwK 40 - PzGr 40 = 91,000

KwK 40 - Gr.38 Hl/x = 685,000

KwK 40 - SprGr = 891,000

1944:

PaK 40 - Total = 3,218,000

PaK 40 - PzGr 39 = 1,276,000

PaK 40 - PzGr 40 = 0

PaK 40 - Gr.38 Hl/x = 535,000

PaK 40 - SprGr = 1,407,000

KwK 40 - Total = 3,652,000

KwK 40 - PzGr 39 = 1,083,000

KwK 40 - PzGr 40 = 0

KwK 40 - Gr.38 Hl/x = 394,000

KwK 40 - SprGr = 2,175,000

KwK 40 includes StuK 40.

It seems possible that a small amount of PzGr 40 was used in both 1942 and 1944, but in numbers so small that they were not included in the report.

As for the effective range of Gr.39 Hl/x, the gunnery manual referred to above sets the maximum range to 1200 meters for Gr.38 Hl/B and Hl/C. Fire for effect (Wirkungsschiessen) was possible upt 600 meters with the first round, at ranges from 600 meters to 1200 meters it was recommended to bracket the target, i.e. to establish the range by firing short and long to establish the actual range.

Gr.38 Hl/x is to be used against all armoured targets, but only against "tanks, difficult to combat" if no PzGr 39 is available.

I would assume that the latter comment means that targets easy to engage like stationary vehicles and vehicles at ranges shorter the 600 meters should be attempted with Gr.38 Hl/x. Obviously, trying hit a moving tank at 1000 meters with this round would be difficult!

Claus B

[Claus B]

Originally posted by Brian:

Funny, thats not what Hogg suggests at all, MBB. He makes the point that for the Pak40 it was issued after the PzGr40 was withdrawn because of short supply. So, I think we have to be very careful at not overcontentration on only one aspect of the use of the round - in tanks - at the expense of where it was used far more - in anti-tank guns.

Hogg is wrong here, as can clearly be seen from production and expenditure figures for PzGr 40 and Gr.38 Hl/x.

PzGr 40 was always a marginal round for the 7,5cm PaK/KwK/StuK guns and was only used in quantity in 1943 and withdrawn at the end of that year. Gr.38 Hl/x was used and produced in much larger quantities in 1942 and 1943, before the PzGr 40 was withdrawn. Also, Gr.38 Hl/x production ceased at the same time production of PzGr 40 was stopped due to lack of tungsten.

Expenditure figures suggest that the Gr.38 Hl/x was used just as much in KwK/StuK 40 guns as it was in the PaK 40. It could be suggested, though, that the bulk of those fired by KwK/StuK 40 was actually fired by the StuK variety, but so far, I haven't found any numbers that can clear that up.

Claus B

[Claus B]

Originally posted by MajorBooBoo:

An interesting thing from the website is:

Sprgr. 34

HE

60/40 Amatol

0.454 kg.

Zdlg. Np. 10

Kl. Az. 23umg

olive green

-

Sprgr. Kw. K. (34)

HE

60/40 Amatol

0.853 kg.

Zdlg. C/98

Kl. Az. 23

olive green

-

Many refs give the Spegr KWK (34) as teh 75mm HE. But what is this Mini-KWK34? Its payload is only one pound of explosive? Given the 75mm diameter and density of steel, it must have been some thick walled type of hybrid round? Perhaps to penetrate concrete or thick bunkers?

The answer is found if you scroll down a bit further on that page.

The SprGr Kw.K. 34 with the large HE content was for the 7,5cm KwK 37 L/24 while the SprGr 34 with the low HE content was for the 7,5cm KwK 40 L/43-L/48.

The former was fired at 420 m/s while the latter took off at 550 m/s through a longer barrel which probably required a shell with thicker walls (same discussion as with the US 75mm HE vs 76mm HE).

Claus B