Soviet Tests: Guns, Ballistic Trials...

[alejandro_]

In the recent days several bloggers with access to Russian archives (TsAMO) have published reports and data on Soviet ballistic tests, focusing on 122mm and 152mm versus Panther and Ferdinand. I have quoted the results in several threads but I had never seen these extracts.

 

There are also several tables comparing penetration values for Soviet and German guns. http://overlord-wot.blogspot.fr has translated the data:

 

 

The first column gives distance to target in meters, penetration is given for a number of guns for both 60 and 90 deg armour slope.

Tested guns (from left to right):

45mm mod. 1938 for T-70 (USSR)

57mm ZiS-4 for T-34 (USSR)

76mm F-4 for T-34 and ZiS-3 for SU-76 (USSR)

85mm D-5 for SU-85 and S-53 for T-34-85 (USSR)

85mm experimental (USSR)

100mm D-10S for SU-100 (USSR)

122mm D-25 for ISU-122 (USSR)

152mm howitzer (?) for ISU-152 (USSR)

152mm gun (?) for ISU-152 (USSR)

152mm OBM experimental (USSR)

57mm (UK)

75mm for M3 (US)

50mm mod.1938 for Pz. III (Germany)

75mm mod.1940 for Pz. IV (Germany)

75mm mod. 1942 for Pz. V Panther (Germany)

88mm for Pz. VI Tiger - L56 - (Germany)

88mm for Ferdinand - L71 - (Germany)

German guns are marked with red square in the pic.

 

Notes:

1. Fraction represents penetration value for AP (above) and APCR (below) rounds

2. Penetration is measured in mm.

 

 

Table 2 basically repeats what has been given earlier, only 105mm K18 gun is added there. Plus the table at the bottom contains the data on armouring in mm (front, side, rear, top) of Panther (it's called a heavy tank there btw), Tiger, and Ferdinand.

 

And a bit of German tactics explained at the very bottom (also translated from the document):

high concentration of tanks on the main attacking directions

taking advantage of accurate guns at long-range combat (1500-2000m)

taking advantage of good armour and right positioning (hiding one's hull)

 

Other tests with very interesting data can be found in this blog:

 

http://world-of-kwg.livejournal.com/

 

 

Tiger-II hit by 152mm round on 2 September 1944 in Olegduba.

 

 

http://world-of-kwg.livejournal.com/39265.html#cutid1

[Mobius]

I wonder if those tables were the result of tests or applying a formula. The German 88mm is only 1mm different than the 85mm up to 1000m. I wouldn't expect test results to be so close and steady but to vary up or down more than that.

[IronsightSniper]

I'd assume the 152 gun was overall, pretty good? Would explain the allegations of "bias" in the early days of WoT, seeing that it's penetration figures were pretty decent and the damage done in the tests seem to be extremely high.

[bojan]

Mobius, those are real tests.

Relation between guns is pretty much same as with Yugo tests.

[alejandro_]

Mobius, those are real tests.

Relation between guns is pretty much same as with Yugo tests.

 

Thanks for clarifying, Is it the case for both tables?

 

The German 88mm is only 1mm different than the 85mm up to 1000m

 

I have looked at other data and there shouldn't be a huge difference unless PzGr 40 ammunition is used. Maybe some of the lower difference is caused by barrel wear. If German guns were tested they were probably captured.

[Marek Tucan]

OTOH the Yugoslavian tests also showed 75 L/48 performing generally the same as 85mm, and here it perfroms significantly worse (and on the other hand 88 L56 should perform better than 75 L48). Of course it is possible that it is only L/43 in the tests, but still the difference seems to be too great. While the long 88 performed poorly vs. highly sloped armor, the numbers here seem to be quite off to me for whatever reason for both 88s. Given the time frame of the tests though (only US short 75 for example), it would seem that the issue might be with the ammunition used?

The 120mm for 88 L56, for example, would be pretty consistent with figures in literature for 8.8cm PzGr. (the original AP issued to AA guns) - in fact it fits exactly (98mm @30° @ 100m). Would it be possible that these tests used older ammunition captured earlier on from the FlaK units?

 

EDIT: Seems that FlaK 41 (88 L74) could use something designated PzGr.39/1, might this be an earleir APCBC preceding PzGr.39/43? Further quick search seems to indicate that 39/1 was improved version of 39, but with narrow driving bands that caused problems when fired from high velocity guns, that's why 39/43 got wider driing bands.

 

EDIT 2: Wiki(I know) suggests that 39/1 was used before enough 39/43 were available in both PaK and KwK 43, but its use was restricted to barrels with less than 500 rounds, after that the performance dropped significantly. Maybe this might be the case here?

Edited August 26, 2012 by Tuccy

[Mobius]

Mobius, those are real tests.

Relation between guns is pretty much same as with Yugo tests.

85mm vs 75mm Pak 40 at very different. The 75mm/L46 v 770m/s is about the same (774m/s) of captured US tests of that gun. But gives much better account of itself in the US tests.

 

It is interesting they have APCR for the 88mm/L71. That is understandable as it was issued in only one month July 1943 for Kursk. So this would have been Ferdinand era 88mm ammo.

 

The tables do show interesting velocities. 76mm is the velocity of the mid war APBC Zis-3. The 122mm D-25 is the velocity of the A-19 of the ISU-122 not the 122mm D-25T of the JS-2. I've never seen the 100mm with 2953/f/s velocity. All I ever saw was 3000f/s which might be the post war APBC round.

Edited August 26, 2012 by Mobius

[Marek Tucan]

The 122mm D-25 is the velocity of the A-19 of the ISU-122 not the 122mm D-25T of the JS-2.

 

Didn't A-19 have the same MV as D-25T, the main difference being in the breech block?

[Mobius]

The 122mm D-25 is the velocity of the A-19 of the ISU-122 not the 122mm D-25T of the JS-2.

 

Didn't A-19 have the same MV as D-25T, the main difference being in the breech block?

It may be who is measuring or when but from data tables I have the D-25T was 746m/s (UK)-781m/s (GDR) and the A-19/D-25 seems to be 800m/s (USSR) - 803m/s(US). I thought one was L43 and the other L46. Unless that's just something with the breech block also. I don't know.

 

 

The old Russian Battlefield site had a report called REPORT ON THE RESULTS OF TESTING OF 100 MM AND 122 MM TANK GUNS AT THE KUBINKA PROVING GROUNDS. Which prints that the 122mm muzzle velocity of 780-790 m.sec with a 25 kg projectile. Which does state the 100mm has a velocity of 900 m/sec. (I guess it was there all the time.)

http://web.archive.org/web/20020126144406/http://history.vif2.ru/library/archives/weapons/weapons5.html

In addition the M1931/37 (A-19) didn't have a muzzle break. Maybe the addition of that that induced some difference.

Edited August 27, 2012 by Mobius

[Marek Tucan]

Checked some dates:

PzGr.39 for 5cm guns was put into service in late 1941, so there is a good guess that majority of ammo stocks captured in USSR that year were of the older PzGr. and PzGr.umg APC.

For 88mm guns first PzGr.39 appeared in 1942, but did not go much to FlaK units - most of ammunition captured by the time of the tests would thus be the PzGr.

For 88/71 and long FlaK, in 1943 ammunition used would be PzGr. or PzGr.39/1, both suboptimal.

[Mobius]

Checked some dates:

PzGr.39 for 5cm guns was put into service in late 1941, so there is a good guess that majority of ammo stocks captured in USSR that year were of the older PzGr. and PzGr.umg APC.

I have another Russian document on the 50mm Pak 38 where the APC data is exactly the same for the ranges on the first document. (Also,90° 200m=74 and 400m=64) and does say something like Pzgr N Pzgr 38. What is different in that is the Pzgr 40 values. With 90° 100m=130, 300m=99.

 

From what vehicles are mentioned the first document the date produced must be after 11/43.

Edited August 27, 2012 by Mobius

[Marek Tucan]

From what vehicles are mentioned the first document the date produced must be after 11/43.

 

by that time there would be long 6 pdr and 75mm M3 available as well,

OTOH all the mentioned "advanced" guns would be already in trials by that time AFAIK, or in service (D5T, S-53, D-10, D-25).

[Mobius]

In April 1944 was the development of an ISU-152-1 prototype with the BL-8 152mm gun. The HE was almost 880m/s and the AP was 850 m/s. I can't find a more powerful Soviet 152mm in WWII. So no 900m/s 152mm gun.

[Marek Tucan]

The OBM-53 gun is marked as "experimental", so it will likely predate BL-8. On the page fold you have also mention of 122mm experimental gun with 1000 mps.

 

Naval 152mm B-53 achieved 950 mps with SAP, 152mm BR-2 had 880 mps with HE.I think there would be a reason a 900 mps gun will remain "experimental" I guess our specialists on Russia will know more but it would probably be a step in the BL-8 development.If BL-8 was available in April 1944, it again shifts the likely date of these tests to 1943.

[bojan]

The OBM-53 gun is marked as "experimental", so it will likely predate BL-8. On the page fold you have also mention of 122mm experimental gun with 1000 mps.

 

Naval 152mm B-53 achieved 950 mps with SAP, 152mm BR-2 had 880 mps with HE.I think there would be a reason a 900 mps gun will remain "experimental" I guess our specialists on Russia will know more but it would probably be a step in the BL-8 development.If BL-8 was available in April 1944, it again shifts the likely date of these tests to 1943.

 

OBM-53 is based on naval 152mm B-38.

BL-8/10 had different ballistics as it was based on 152mm Br-2 gun.

122mm with 1000m/s is 122nn BL-9.

[alejandro_]

For 88/71 and long FlaK, in 1943 ammunition used would be PzGr. or PzGr.39/1, both suboptimal.

 

What do you mean by suboptimal?

Edited August 28, 2012 by alejandro_

[Marek Tucan]

ah yes, meant to write "naval B-38", the "53" got there by mistake Do you have per chance more details about the OBM-53 and BL-8/10 development? Most sources are pretty unclear, that is why it wasn't clear to me if BL-8 waqs development from the naval gun or from BR-2.

 

The 122mm designation seems to be different, I assume it is some development stage for BL-9, but from the (indistinct) letters I will guess it says "BM-50", so full designation OBM-50?

 

Alejandro, apparently PzGr.39/1 was designed primarily for 88 L/56 and when fired from long barrels it was limited to barrels with less than 500 shots fired, as its narrow driving bands both caused more erosion to the rifling and some other problems (gas leakage maybe? Stability? Did not find specifics, only that it was problematic). That is why the 39/43 was developed, with wider driving bands.

[Mobius]

Unfortunately they clipped off the right side where the 88/L71 values are.

 

Isn't it interesting the evolution of the ammo took during the war. We often see it as being static, that at the end. But, delving in deeper it is dynamic.

[Max H]

Isn't it interesting the evolution of the ammo took during the war. We often see it as being static, that at the end. But, delving in deeper it is dynamic.

 

Rather like during the cold war. Or the evolution of rifle ammo in WW1

[Marek Tucan]

By the way, was PaK 40/KwK 40 using PzGr.39 from the beginning, or was there also some older ammunition used?

[Mobius]

By the way, was PaK 40/KwK 40 using PzGr.39 from the beginning, or was there also some older ammunition used?

I'm pretty sure it was PzGr.39 all the way.

I wonder if the Pak 38 got some off brand PzGr 40 later in the war. Like in the Yugo tests there was an APCR called a 40w.

I wonder if this is what was tested for the Pak 38 APCR tests.

[Marek Tucan]

AFAIK no 40W APCR for 5cm PaK/KwK, and for 7.5cm it was late war austerity measure. How well did it work anyway? IIRC bojan mentioned that the Yugoslavian manuals recommended it being used against fast, lightly armored target.

[Mobius]

I was trying to match the '122mm D-25 for ISU-122 (USSR)' gun with other data I have. What is surprising this matchs within 1mm penetration for the same velocity as in East German 1960 table for 122mm APBC. I thought the East Germans were using their own standard, maybe the old German WWII standard. Apparently not. They must have reprinted Soviet data and not come up with it on their own.

[Marek Tucan]

Or they used Soviet std. I think so did Czechoslovakian army, when it went to WarPac standard.

[Mobius]

Or they used Soviet std. I think so did Czechoslovakian army, when it went to WarPac standard.

Ok, that is possible too. The penetrations at the same velocities (other than 1000m) vary slightly which is what you would expect at live tests.