CMFB patch released

NUTTERNAME

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I think the following visuals will show some differences between the US M62 and German PzGr 39...There are clearly design differences as far as HE filling, Cap shape and angles, and I suspect BC size also. I don't believe the US design would do well against sloped armor. I thought I had the US test on the PzGr 39 somewhere showing hardness...

View attachment 53892

View attachment 53893

Edit: I forgot my main point....that is, note the three part design to the PzGr 39. It is denoted by the angled lines.
 
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mOBIUS

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The US small scale tests gives the hardness in Rockwell numbers which they think the German 75mm cap is ~400 BHN and body ~680BHN. The BIOS report says the body is around 600 BHN but the caps are made as hard as possible. Though I can't locate a BHN number.

I think a guy who posted on the now defunct WW2aircraft site forum and who found 'Die Vorgange beim Beschuf von Panzerplatten' posted the nose hardness numbers.
[Edit]
I found a Rexford post : that says the German nose hardness was 61 on the Rockwell C-scale. ~610 BHN or 680 on another scale. ???
 
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The US small scale tests gives the hardness in Rockwell numbers which they think the German 75mm cap is ~400 BHN and body ~680BHN. The BIOS report says the body is around 600 BHN but the caps are made as hard as possible. Though I can't locate a BHN number.

I think a guy who posted on the now defunct WW2aircraft site forum and who found 'Die Vorgange beim Beschuf von Panzerplatten' posted the nose hardness numbers.
[Edit]
I found a Rexford post : that says the German nose hardness was 61 on the Rockwell C-scale. ~610 BHN or 680 on another scale. ???
The Germans really made a good engineering effort as far as the PzGr 39 design.

They were basically trying to find a solution to multiple problems. They were facing 3 major industrial nations that were producing different MBT in 1942. Even the Soviets presented multiple threats in the T34 and KV designs of protection. They had to come up with a projectile design that could take on most comers.

The basic projectile PzGr 39 (and its close cousin the PzGr 39/42) was fielded in:

Pak 40
KWK 40
KWK 42
Pak 39
StuK 40
StuK 42

There were about 5 plants making these projectiles as a sub-component of fixed cartridge ammunition. I have read posts by a EOD person claiming it is the third most found projectile. It could certainly be claimed that these projectiles, from all these platforms, accounted for the vast majority of enemy AFV destruction.

There is very little evidence that the Germans produced APCR for the Pak 40 or Panther weapon (in anything but field trial numbers). Mostly because, IMO, they did not need it given the velocities these weapons had. The Panther APCR, BTW, was a different design than the other listed weapons above. Its 'bolt' was the larger sized bolt from the squeeze-bore ATG. Edit: Tiger I and panther APCR shared the same bolt
 
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mOBIUS

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The Germans really made a good engineering effort as far as the PzGr 39 design.
There is very little evidence that the Germans produced APCR for the Pak 40 or Panther weapon (in anything but field trial numbers). Mostly because, IMO, they did not need it given the velocities these weapons had.
Information I have says that the Germans supplied their new ATG/tanks with APCR for the Kursk offensive but withdrew it in August. So most APCR available from then on was probably left over from this stock.
The data I have on the 75mm/L70 APCR is pretty consistent between US and German penetration. Except that found in Spielberger's Panther book which seems a bit odd.

The Panther APCR, BTW, was a different design than the other listed weapons above. Its 'bolt' was the larger sized bolt from the squeeze-bore ATG.
[Edit] Had to correct my first post here. I had done one table in yards instead of meters. It now shows that the 75mm /L70 APCR has a slight disadvantage (110-130m) in a range/penetration vs. range/velocity comparison.

For example: L48 (MV 930) APCR penetrates at 500m what the L70 (MV 1120) does at 1610m. While the L48 has a V at 500m what the L70 has at 1720m.
 
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NUTTERNAME

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I will have to double check on the Panther APCR. I believe it was your buddy Miles Krogfus who claimed that the squeeze gun 75mm and Panther used the same bolt.

In any case, these are production numbers as far as stock on November 1942 for the Pak40. (thousands)

7,5 cm Sprgr Patr 34 (7,5 cm Pak 40): 533.1
7,5 cm Gr Patr 38 Hl (7,5 cm Pak 40): 917.6
7,5 cm Pzgr Patr 39 (7,5 cm Pak 40): 945.3
7,5 cm Pzgr Patr 40 (7,5 cm Pak 40): 1.7
7,5 cm K Gr rot Nb (7,5 cm Pak 40): 30.3

That is just for the Pak 40 antitank gun and any Marder types mounting that weapon. Clearly 7,5 cm Pzgr Patr 40 is a minority type. Supposedly in the field in January 1943.

Compare those numbers with the rare 7,5 cm Pak 41...

7,5 cm Sprgr Patr 41 (7,5 cm Pak 41): 25.2
7,5 cm Pzgr Patr 41 H K (7,5 cm Pak 41): 63.3
7,5 cm Pzgr Patr 41 St K (7,5 cm Pak 41): 0

The Panzer IVs and StuG...

7,5 cm Sprgr Patr 34 (7,5 cm Kw K 40 and Stu K 40): 498.4
7,5 cm Gr Patr 38 Hl (7,5 cm Kw K 40 and Stu K 40): 412.8
7,5 cm Pzgr Patr 39 (7,5 cm Kw K 40 and Stu K 40): 747.6
7,5 cm Pzgr Patr 40 (7,5 cm Kw K 40 and Stu K 40): 22.1
7,5 cm Gr Patr Nb (7,5 cm Kw K 40 and Stu K 40): 22.6

I would certainly assume that there were more Pak 40 around than there were panzer IV and StuG (L43 and L48) in November 1942. Yet, they seem to have less than a couple thousand rounds of APCR?

Check these numbers for the 7,62 cm Pak 36 and F K 39...

7,62 cm Sprgr Patr 39 (7,62 cm Pak 36 and F K 39): 1042.4
7,62 cm Pzgr Patr 39 rot (7,62 cm Pak 36 and F K 39): 476.5
7,62 cm Pzgr Patr 40 (7,62 cm Pak 36 and F K 39): 77.8

I suspect that Kursk and the rest of 1943 may have been the heyday for most German use of APCR. The Germans pulled the 7,5 cm Pak 41 out of service, and sometime in 1943 recalled all APCR ammunition. They also had the bolts that were not yet assembled into ammunition stocked as a reserve. The numbers of these made for the smaller calibers is remarkable.
 
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NUTTERNAME

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A stock 'snapshot' a year later Dec 1943...

December 1943:
680,000 3.7 cm Pzgr. 40 for the 3.7 cm Pak and about 269,000 3.7 cm Pzgr. 40 for the Kw.K.
207,000 5 cm Pzgr. 40 and 40/1 for the 5 cm Pak 38.
298,000 5 cm Pzgr. 40 and 40/1 for the 5 cm Kw.K. (L/42).
32,000 5 cm Pzgr. 40 and 40/1 for the 5 cm Kw.K. 39 (L/60).
About 15,000 7.5 cm Pzgr. 40 for the 7.5 cm Kw.K./Stu.K. 40.
55,000 7.5 cm Pzgr. 41 (H.K.) for the 7.5 cm Pak 41.
60,000 7.6 cm Pzgr. 40 for the 7.6 cm Pak.

Considering how many 7,5 cm L43 and L48 were around in December 1943, APCR ammo for this weapon was actually getting much rarer. The Pak 40 is not even listed.
 
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Actually, he claimed that Tiger I and Panther shared a core...

Miles Krogfus wrote:
Total Krupp production of all tungsten cores:
15 dia. 58 mm length for 42 mm Pzgr 41: 424,205
16 dia. 58 mm length for 37 mm Pzgr 40: 1,931,737
21 dia. 75 mm length for 50 mm Pzgr 40 and 40/1: 1,911,102
28 dia. 110 mm length for 75 mm Pzgr 40, 75 mm Pzgr 41, 76.2 mm Pzgr 40: 193,040
30 dia. 120 mm length for 75 mm PzGr 40, 88 mm Pzgr 40: 24,359
36 dia. 140 mm length for 88 mm Pzgr 40: 39,485
That means the Tiger I and Panther could only have 24,359 between them! That is, IF they were all assembled and delivered and not recalled.
 

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A stock 'snapshot' a year later Dec 1943...

December 1943:
680,000 3.7 cm Pzgr. 40 for the 3.7 cm Pak and about 269,000 3.7 cm Pzgr. 40 for the Kw.K.
207,000 5 cm Pzgr. 40 and 40/1 for the 5 cm Pak 38.
298,000 5 cm Pzgr. 40 and 40/1 for the 5 cm Kw.K. (L/42).
32,000 5 cm Pzgr. 40 and 40/1 for the 5 cm Kw.K. 39 (L/60).
About 15,000 7.5 cm Pzgr. 40 for the 7.5 cm Kw.K./Stu.K. 40.
55,000 7.5 cm Pzgr. 41 (H.K.) for the 7.5 cm Pak 41.
60,000 7.6 cm Pzgr. 40 for the 7.6 cm Pak.

Considering how many 7,5 cm L43 and L48 were around in December 1943, APCR ammo for this weapon was actually getting much rarer. The Pak 40 is not even listed.
They certainly have stocked up on Pzgr.40 for the 37mm and 50mm L42 which will never be used.
OTOH subtracting the cores for 7.5 cm Pzgr. 41 (H.K.) and 7.62 cm doesn't leave that many for the 7,5cm 40 guns.
 
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NUTTERNAME

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Given the small number of 7.5 cm Pak 41 built (150), the weapon would still have combat capability given an ammunition on hand in Dec 43. I always thought it should have been built on a chassis like the Marder. Its velocity gave it point and shoot capabilities at most ranges.

The Germans built some crazy number of those stick bombs for the 37mm ATG. Like 900K. I suppose the 37mm APCR was used for the Stukas with the twin 37mm cannons.

An interesting bit of math is that the Total 28 dia. 110 mm length for 75 mm Pzgr 40, 75 mm Pzgr 41, 76.2 mm Pzgr 40: is 193,040

If we add the Dec 43 stock together, we get 130,000, meaning that 63K might have been consumed up to that point in the war. Given the ratios suggests that 7K were fired off by Panzer IV long and StuK 40. That is actually a very small number given the number of those weapons that were increasing fielded in 1943.
 

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An interesting bit of math is that the Total 28 dia. 110 mm length for 75 mm Pzgr 40, 75 mm Pzgr 41, 76.2 mm Pzgr 40: is 193,040

If we add the Dec 43 stock together, we get 130,000, meaning that 63K might have been consumed up to that point in the war. Given the ratios suggests that 7K were fired off by Panzer IV long and StuK 40. That is actually a very small number given the number of those weapons that were increasing fielded in 1943.
I'm not clear on what the exact meaning of "production numbers as far as stock on November 1942". I assume it is the number in inventory stocks, not the number produced that year. If that is the case then the following numbers of Pzgr.40 are stock on hand.
1942
77.8k = 76.2mm
23.8k = 75mm Xx.K. 40
63.3k =75mm 41
total 164.3k

1943
60k = 76.2mm
15k = 75mm Xx.K. 40
55k =75mm 41
total 130k

As a total of 193k bolts were produced there could only be 28.7k additional rounds produced and consumed among the three types sometime during the war. At that it sure doesn't look like many Pzgr40 were passed out to all the Panzer IV long, StuK 40 and Pak 40 guns.
Yet, Russian, British and the US captured enough to test them.
 
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NUTTERNAME

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I'm not clear on what the exact meaning of "production numbers as far as stock on November 1942". I assume it is the number in inventory stocks, not the number produced that year. If that is the case then the following numbers of Pzgr.40 are stock on hand.
1942
77.8k = 76.2mm
23.8k = 75mm Xx.K. 40
63.3k =75mm 41
total 164.3k

1943
60k = 76.2mm
15k = 75mm Xx.K. 40
55k =75mm 41
total 130k

As a total of 193k bolts were produced there could only be 28.7k additional rounds produced and consumed among the three types sometime during the war. At that it sure doesn't look like many Pzgr40 were passed out to all the Panzer IV long, StuK 40 and Pak 40 guns.
Yet, Russian, British and the US captured enough to test them.
Yes, it would actually be completed stock of assembled cartridges. Not necessarily delivered or released to units yet. But, the 193K is total bolt production. That is, not assembled cartridges.

Your analysis regards the 28 dia. 110 mm length bolt, of course. Its worth noting that the 15K at the end of 1943 is for just the KWK 40 weapons (7,5 cm L43 and L48). That is, no Pak 40 which shared this projectile design.

It might be interesting to know the actual numbers of 76.2 mm weapons left on hand at the end of Dec 1943. Certainly, the Pak 41 was a minority weapon. The Pak 40 was by this time replacing most front line ATG units weapons. Also, The KWK 40 and StuK 40 AFV were becoming the predominate weapons.

As a comparison...

21 dia. 75 mm length for 50 mm Pzgr 40 and 40/1: 1,911,102
28 dia. 110 mm length for 75 mm Pzgr 40, 75 mm Pzgr 41, 76.2 mm Pzgr 40: 193,040
Almost 10X the manufactured numbers. People should realize that Pak 38 and even 50mm armed tanks did not have the production numbers of the Pak 40 and KWK/StuK 40 weapons. Even in 1943, panzer IIIs were on the way out.

There is also some data, dealing in tonnage, in regards to recalled ammunition, and never assembled bolts. I know the Soviets got some APCR after Kursk and did testing. Are there war time tests by the US and British? They probably did capture enough 50mm etc. in North Africa.

I wonder if the German decision to halt/recall manufacture might also have factored in that the Soviets had really cut back on a Heavy tank manufacture. The new German 7,5 cm weapons were doing decent work as is. The Soviets pushed hard in 1943 after Kursk and the Germans were really facing hoards of two man turret tanks and they were losing to these. The Soviet losses were tremendous but the Germans had plenty of problems themselves with the panther tank issues and bombings hurting StuG production and trying to train and equip an army that basically was facing overwhelming numbers in a vast territory. They needed greater production and using Tungsten as 'shot' did not fit into the reality of machining parts. In fact, just making normal APCBC projectiles requires Tungsten carbide to machine the finish. This actually 'consumes' the tungsten as it flakes off.

In Dec 43, there was a fleet of about 1700 panzer IV and possibly an equal number of StuK 40.
 
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mOBIUS

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Are there war time tests by the US and British? They probably did capture enough 50mm etc. in North Africa.
There are brief circulars but like the one on 50mm Pak 38 in 1943 gives the penetration as 'Unconfirmed on AP 40 at 330 yards @ 20° as 90mm'.
 

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There are brief circulars but like the one on 50mm Pak 38 in 1943 gives the penetration as 'Unconfirmed on AP 40 at 330 yards @ 20° as 90mm'.
I suppose the 5,0 cm bolt could be used in the 7,5 cm PzGr 40 design by just using a sleeve. The extra velocity possible from the larger cartridge case would surpass the 5,0 cm performance. The Soviet 85mm used a very small bolt, I believe.
 

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The Soviet 85mm used a very small bolt, I believe.
Might have been a copy of an early German projectile. According to the Russian Battlefield Soviet APCR was unstable and thus inaccurate. But German APCR and US HVAP was at least as accurate as the regular AP round. In Archive Awareness site there is an article on comparison testing different Soviet APCR designs.

I read that the Germans had restricted the use of APCR on enemy heavy tanks, KVs. I wonder what the practical result of this was? It would seem to me it might result in the tankers off loading the APCR until needed instead of limiting their ammo supply by having a couple rounds in their racks that they almost never use. I don't have any evidence of this but Bruno Freisen doesn't mention to ever using APCR in his book, Panzer Gunner.
 

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I read that the Germans had restricted the use of APCR on enemy heavy tanks, KVs. I wonder what the practical result of this was? It would seem to me it might result in the tankers off loading the APCR until needed instead of limiting their ammo supply by having a couple rounds in their racks that they almost never use. I don't have any evidence of this but Bruno Freisen doesn't mention to ever using APCR in his book, Panzer Gunner.
Here is an interesting document that I have not seen before. Appears to be a penetration curve(s) for the very rare 8,8 cm L56 APCR. It seems to show penetration at 100m and 600m curves for a set armor hardness and varies with angle.

The APCR for the Tiger I was released for troop use in January 1943, btw. I wonder if any FlaK 18 units got any. They would need different primers I would assume since the Tiger I is electric and not percussion.

As far as how the APCR was used in German units, I have not read much. But, I would assume that it might be reserved for Platoon and Company HQ tanks in Panzer units. It might be given to Panzerjaeger units like the Jagdpanzer IV as a priority. Especially since their mission is to fight tanks. In fact, I would expect these units to also prefer HEAT over HE for the same reason.

View attachment 54127
 

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Here is an interesting document that I have not seen before. Appears to be a penetration curve(s) for the very rare 8,8 cm L56 APCR. It seems to show penetration at 100m and 600m curves for a set armor hardness and varies with angle.

View attachment 54127
Is that tungsten? 67mm at 100m with 30° is not anything to write home about.
 

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Is that tungsten? 67mm at 100m with 30° is not anything to write home about.
I thought you might like that.

Note the hard armor? The extreme drop off with slope? It actually looks like the early arrow-head 5cm rounds. To be honest, I have never seen a 8,8 cm PzGr 40 before. The pic shows a nice cutaway like they do at the shell-collector sites.

Tigers never really had the fleet numbers, so if they had APCR, and since they were the only ones really that would use it, they might get some for each Tiger. But, really, I can see drawbacks in having more than two types of ammunition in even a elite tank crew. Having HEAT, SMOKE, APCR, AP and HE requires a lot of shuffling around. In 1944, the Germans had training/manpower issues. many gunners did not get many rounds to fire in training, and these were Ub boots. having just AP and HE makes a lot of sense.

I have read that 5 cm L42 either did not use the APCR due to it not working in the guns correctly, or that it had no real benefit over regular AP, and it was worthless against sloped/oblique hits.
 

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I thought you might like that.
.
I hope you didn't dummy that up.
It is right out of
http://www.lexpev.nl/downloads/handbuchderflugzeugbordwaffenmunition19361945.pdf
It is for a 3 cm flak gun. (label missing so difficult to tell what caliber it is) See page 30 Apparently 1918 was a good year for flak guns as there are 3cm, 3.7cm and 8.8 cm flak 18 guns.

It thought I saw it before. I use tables from that pdf in the latest page of my website. http://www.panzer-war.com/page50.html

The one data source I have for 88/L56 APCR has 165mm @ 30° for 100m.
 
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mOBIUS

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I just took it from one of the war thunder threads. No way that can be right.
Unfortunately that is one of the drawbacks of sites like Warthunder and WOT. They can pollute Google searches for historic data as they are popular and come to the top of the list. Sometimes they reveal gems, but many other times they recycle bad data.
 
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