Showing posts with label 75L/43. Show all posts
Showing posts with label 75L/43. Show all posts

Thursday, 20 October 2016

7.5 cm Sprenggranate 34

Much talk is dedicated to various armour piercing munitions, but high explosive shells are no less important for cannons. Let's take a look at the data sheet for high explosive ammunition of a 7.5 cm KwK 40 L/43 gun.

"Spreng-Granate 34. Vo = 550 m/s

Without delay (o.V.): use against strongpoints, AT guns and riflemen, masses of targets, against tanks use only with impact fuse.
With delay: (m.V.): use against targets behind cover, or, as an exception, against live targets with ricochet.

Wednesday, 28 August 2013

Combat Performance of 7.5 cm and 8.8 cm Guns

I've posted tons of very technical information on the performance of various 75 and 88 mm German guns. However, all that really doesn't say much about how well these guns performed on the battlefield. Thankfully, Colonel P.S Igumnov did all the hard work for me, and all I have to do is show figures from his doctoral thesis, "Investigation of Destruction of Domestic Tanks (using the experience of the Great Patriotic War).

Here's a nifty data set, distances of penetrations from the two aforementioned calibers:


And a nicer looking version of the data, compiled by fat-yankey

The data is not surprising at all. The majority of 88 mm hits are at 600-800 meters, exactly the range at which a Tiger would be engaging a T-34 according to the Tigerfibel. The mythical 2 km shots represent a negligible amount of the total. The 75 mm caliber favours closer engagements, at about 400-500 meters.

Saturday, 2 March 2013

Penetration

If you read the World of Tanks forums, odds are you've seen this penetration table. Overlord even talked about it on his blog. For those unfamiliar with it, let me give you a quick translation. 

The column on the left is distance to target in meters. The first row lists the guns: "45 mm tank gun model 1938 on tank T-70", "57 mm gun ZiS-4 on tank T-34", "76 mm gun F-34 on tank T-34 and ZiS-3 on SU-76", "85 mm gun D-5 on SPG SU-85 and S-53 on tank T-34-85", "85 mm gun of increased power, experimental", "100 mm gun on SPG SU-100", "122 mm gun D-25 on tank IS and SPG ISU-122", "152 mm howitzer on SPG ISU-152" (ML-20), "122 mm gun of increased power OBM-50, experimental" (BL-9), "152 mm gun of increased power OBM-53, experimental" (BL-8, BL-10), "57 mm English gun" (6 pounder), "75 mm American gun on tank M3 Lee" (M2 tank gun), "50 mm gun Model 1938 on tank PzIII", "75 mm gun Model 1940 on tank PzIV", "75 mm gun Model 1942 on tank Panther", "88 mm gun on tank Tiger", "88 mm gun on SPG Ferdinand". 

The V0 value indicates the muzzle velocity of the shell. Under each gun name, there are two columns: one for an armour plate angled at 60 degrees from horizontal and one for an armour plate angled 90 degrees from horizontal. When two values are shown in one box, the numerator is the performance of a caliber AP shell, the denominator is the performance of a subcaliber AP shell. 

CAMD RF 81-12038-303

If you've seen it before, you also have heard criticism aimed its way. "Propaganda!" some people cry. "The 8.8L/71 penetrated 203 mm at 100 meters, not 168! This document is not to be trusted!"

They are wrong about the propaganda bit, as this was a classified internal document, used by engineers to analyze the required armour and firepower for future tanks. It would be pretty foolish to falsify these numbers. Besides, a dense table of data isn't exactly the best for propaganda material.

However, the 8.8L/71 did penetrate 203 mm of armour... when the Germans tested it. German penetration testing standards were different from the Soviets'. German penetration tests were performed with specially selected shells, against armour angled at 30 degrees. If a shell could penetrate the effective armour thickness 50% of the time (several times in a row, depending on the shell caliber), that penetration is recorded as how much that shell can penetrate.

Obviously, the Soviets didn't get courtesy shipments of special testing ammo, so they used whatever was captured along with German tanks. Therefore, these tests give a better indication of how a tank would perform on the battlefield. The Soviets had two penetration standards. When only one penetration value is shown, 75% of the shell fragments end up behind the armour plate. When two penetration values are shown, the two values are for 20% penetration (possible penetration) and 80% penetration (guaranteed penetration). So, as you can see, according to this data, while the 8.8L/71 could penetrate 203 mm of armour using special shells with 50% probability, it could only penetrate 168 mm using regular shells with 75% probability.

This document is very interesting, because it brings together most common guns of WWII (regrettably, some interesting ones are missing, like the 17 pounder or the Sherman's 76 mm gun) under the same testing conditions. This makes the comparison between the various guns much easier than having to pick through various sources, and then tring to figure out all the different test conditions.

Now, time to do some comparisons! You may have read a lot about the unprecedentedly devastating power of the Tiger's gun. However, it penetrates 120 mm at most. This is definitely high for WWII, but similar performance is reached by the Soviet 57mm ZiS-4, that was mounted on some T-34s since 1941, as well as the 85mm guns from the SU-85 and T-34-85. With APCR, even the ordinary T-34's 76 mm gun surpasses the Tiger in penetration (albeit at the expense of accuracy).

The Tiger's successor, the Tiger II, reaches better results with the 8.8L/71 gun, 168 mm. However, the D-25 gun on the IS-2 (which I compared to the 88 mm guns before) achieves nearly as much penetration, and the D-10T gun on the SU-100 (also tested on the T-34-85) surpasses it.

The Panther's long 75 mm gun also has very good penetration, and is comparable to the experimental 85 mm gun. Of course, the experimental OBM-50 and OBM-53 surpass all other guns on this table with huge penetrations of 230 mm and 244 mm, respectively. This would have been enough to take out a Maus tank, if Germany had ever sent any into battle.

In conclusion, the myth of superior German tank guns is, yet again, proven false.

See more penetration values in Penetration, part 2.