Weapons Data

Introduction

Weapons data provides information on all tank and anti-tank weapons of World War II. This section includes this Introduction page and one page for each country: Britain, France, Germany, Italy, Japan, the Soviet Union, the United States of America and Other Countries. This introductory page includes background information on the presentation of the weapons data which is applicable to all nations:

Scope

The data presented in this section is limited to gun penetration data, vehicle armour schemes, and data on armour hardness and quality. I have made no attempt to cover development history or to include more general information about individual weapons as this is well covered elsewhere in numerous books and web sites. You are encouraged to read further from the many sources I have used and these are all listed in the Bibliography.

Country of Origin

Weapons are presented according to their country of origin. Weapons which were used or built under licence, without modification, are listed under the country which originally built or designed them. Examples of this are Britain and the Soviet Union using USA weapons under the Lend Lease arrangement (which are presented in the USA data tables), British tanks being built under licence in Canada (which are presented in the British tables), and captured equipment used without modification such as the German use of captured Soviet T–34s (which are presented in the Soviet tables).

Weapons which were captured or bought, and subsequently modified before being used, are listed under the country which modified them. Examples of this are British modifications of USA weapons such as the Grant Mk.I and the Sherman Mk.VC Firefly (which are presented in the British data tables) and German conversions of captured Soviet 76mm anti-tank guns (which are presented in the German tables).

There are some weapons that do not fall neatly into the two categories given above. Czechoslovakia designed and produced several weapons before annexation by Germany in 1939. After Czechoslovakia ceased to exist, the Skoda company continued to develop and produce many weapons under German rule. Germany also developed new ammunition for existing Czechoslovakian guns. I have chosen to present the pre–1939 weapons in the Czechoslovakian data tables, even if new ammunition was developed later by Germany, and the post–1939 weapons in the German data tables. Weapons under development or production, but not yet in service, at the time of the German annexation are listed in the German data tables.

Weapon Identification

I have taken great care to specify the correct vehicle and gun names. This is not always as simple as it sounds. Sometimes official names will be changed but the old name remains in use, making it appear that there are two different weapons. Tank guns are often developed from artillery guns but may have completely different names. If there is gun penetration data for one version of a gun it may be applicable to other versions, or it may not. To assist in correct identification of guns the calibre and length are specified, so that if two guns have the same values for both then they are probably related and may even be identical.

Calculation of Gun Lengths

The calibre (or bore) of a gun is the internal diameter of the gun barrel. The length of the gun, without the muzzle brake if fitted, is expressed as a multiple of the calibre. So a 40mm/L52 gun has a calibre (or bore) of 40mm and a length of 40mm × 52 = 2.08 metres. Some countries (such as the USA) measure the length of the gun barrel from the mouth of the chamber to the end of the barrel; this measurement is called the bore length. Continental European countries (France, Italy, Germany and the Soviet Union) measured from rear face of the breech ring to the end of the barrel. This means that the calculated gun length is longer using the second method.

Diagram of calibre length measurements

From a technical viewpoint the bore length is a better measurement of a gun’s performance because it gives the working volume available to propel the projectile. However as there is so much information on World War II guns already published using the European method (mainly German and Soviet guns) it would be confusing to insist on using the bore length. Consequently the data tables use the second (European) method to facilitate comparison of guns.

Continuous Improvement of Ammunition

Ammunition research and design was carried out by all nations. Improved ammunition could significantly enhance the penetration ability of a gun. It is not sufficient, therefore, to quote only the gun name when presenting penetration data, the ammunition type must also be specified. This is not always possible as many sources, for the sake of brevity, only quote the data for the most recent or most capable ammunition type. As many guns remained in service after 1945 these ammunition types may not even have been available in World War II, the period of interest of this web site.

Another problem is that many ammunition types were developed and tested, but they may not necessarily have been issued to units in the field. This was often the case with APCR rounds as most used tungsten which is a rare and expensive material. The few APCR rounds issued may have been sent only to select units. In the case of Germany, the Allied bombing and blockade effectively halted the production of tungsten cored projectiles in 1943. The ammunition was still in use by Germany in 1944 (and perhaps 1945) from stockpiles, but only in small numbers. Ammunition availability is specified where known.

Determining Penetration Capability

There are three main factors which affect penetration capability and which must be taken into account when comparing gun penetration between different nations. While this section does not attempt to present a detailed analysis it does present some useful generalisations. The three main factors are: the hardness of the armour plate used as a target during testing; the quality of the ammunition used during testing compared to normal production quality; and the definition of penetration used for tests.

Hardness of Target Armour Plate

The hardness of the target armour plate used during gun ballistics tests must be taken into account when comparing gun penetration data. This usually varied considerably from country to country, and even for one country there were often different hardness standards used for different target plate thicknesses.

Target armour plate can be either RHA or FH and is made in the same way as vehicle armour plate. Test results for the USA and Britain often included both types of target plate, although results quoted on this web site are RHA unless otherwise stated.

Ammunition Quality Used During Testing

British Ammunition Quality

The British used ammunition of ‘calibration’ standard for testing, which was top quality.

German Ammunition Quality

The British Intelligence Objectives Subcommittee report German Tank Armour dated 1946 includes information that an approximate 5% to 10% deficit could be demonstrated by production quality ammunition compared to that used for testing.

Soviet Ammunition Quality

The ammunition quality used for Soviet testing is unknown. However Soviet quality control was generally poor and ammunition was substandard up until about 1944, which would degrade penetration in unpredictable ways. I would expect that this means that some ammunition would perform better than predicted and some worse, or even considerably worse.

USA Ammunition Quality

There is some evidence to suggest that the USA used normal production quality ammunition in tests.

Definition of Penetration

Even after the hardness of the target armour plate and the quality of ammunition used during testing are taken into account, there may be further apparent differences in gun penetration performance due to the way each nation carried out penetration tests. The definition of when a projectile penetrates an armour plate differs from country to country, and sometimes there is more than one definition for a particular country. It is most often defined as when at least half (sometimes two-thirds to three-quarters) of the projectiles fired at the target plate achieve ‘penetration’. The trouble starts when trying to define ‘penetration’. For most countries this means the projectile has to completely pass through the target armour plate, however there were some variations to this; e.g., for British 2–pounders only 20% of the projectile had to pass through (but it had to do so on 80% of occasions instead of 50%).

Another complication is that there was different criteria to measure the quality of armour plate used for the production of armoured vehicles, than the criteria used to measure gun penetration performance. In the first case the tests determine how much protection an armour plate can provide under all conditions, and the criteria used is usually when the plate first starts to fail. On the other hand when measuring gun penetration performance the purpose of the tests is to establish what penetration could be expected, on the average, for that particular ammunition type. The two criteria used would obviously be very different.

It doesn’t help matters that in the USA one definition is called the ‘Army’ criteria and another is called the ‘Navy’ criteria. For a while there I had naively assumed that one critieria was used to measure the performance of Army projectiles, and the other for Navy projectiles. However this is not so, in fact all USA gun penetration performance is assessed to the Navy criteria regardless of the service arm actually conducting the test. Silly me.

It is sufficient to say that although each country has slightly different definitions of penetration, these effect of these differences is usually small. The British W/R limit criteria (in general use by 1942) and USA criteria are essentially the same and have negligible differences. German criteria may be slightly higher by 0% to 2%, however any difference is slight and may not be statistically meaningful. The Soviet criteria is higher than the British and USA criteria by a small amount, 2% to 3%. The result of this higher criteria is that the gun data tables indicate a lower penetration under the Soviet criteria than compared to the USA criteria.

Tabulated Data

Gun Penetration Data

The Gun Penetration Data tables include the penetration capability of all guns capable of firing an anti-tank projectile for each ammunition type. Many AA and artillery guns were issued with anti-tank ammunition and these are also included. The angle of the target armour plate is measured from the vertical, so 0° is a vertical plate. Selecting [V] near the weapon name will display a view of the gun if available.

Gun Accuracy Data

The Gun Accuracy tables show the results of two types of tests: dispersion and firing.

Dispersion tests show the percentage of projectiles that will hit a 2.5m × 2m target during controlled test firing. The pattern of dispersion is assumed to be centred exactly on the target. These results give a good theoretical comparison of guns and ammunition types, without considering the complicating effects of human error.

Firing tests show the expected percentage of projectiles that will hit a 2.5m × 2m target by a gunner during practice firing on a gun range. It is obtained by doubling the dispersion pattern obtained from the dispersion test data. The British, Germans and Italians all considered this to be a close approximation of the accuracy obtained by troops in practice firings and, if they remained calm, in combat when the range to the target is known. Due to errors in estimating the range and many other factors, the probability of a first round hit was much lower than shown in these tables. However, the average, calm gunner, after watching tracer from the first round, could achieve the accuracy shown on subsequent shots.

Armour Data

The Armour Scheme tables are divided into two pages for display: turret armour and hull armour.

Turret Armour

The Turret Armour page includes the armour thickness and angle (where known) of all sides of the vehicle’s turret (or superstructure for a vehicle with no turret). The angle of the armour is measured from the vertical, so 0° is a vertical plate and 90° is a horizontal plate. Since it is often difficult to visualise the shape of the vehicle from raw tabulated data, selecting [V] near the vehicle or model name will display a three-quarter front view and a three-quarter rear view (if available). Where these are unavailable a side view is shown.

The turret page includes the main gun fitted to the vehicle. Selecting this will display the appropriate Gun Data table.

The turret page includes the assembly (welded or riveted) and specification year for each vehicle. Selecting the specification year will display the Hardness Data table for vehicle armour plate. It is necessary to use the specification year to determine the BHN of the vehicle armour. Note that the specification year is not the same as the production year, although in many cases I have used the first production year as a best guess for the specification year.

The armour plate is always RHA unless specified otherwise.

Hull Armour

The Hull Armour page includes the armour thickness and angle (where known) of all sides of the vehicle’s hull. The angle of the armour is measured from the vertical, so 0° is a vertical plate and 90° is a horizontal plate. Since it is often difficult to visualise the shape of the vehicle from raw tabulated data, selecting [V] near the vehicle or model name will display a three-quarter front view and a three-quarter rear view (if available). Where these are unavailable a side view is shown.

The armour plate is always RHA unless specified otherwise.

Hardness Data

The Armour Hardness tables include the armour hardness and quality (where known) of armour plate used for gun ballistic tests and vehicle manufacture. The hardness is given as a BHN measurement, which is determined by the specification used for the armour plate and its thickness.

The specification is tabulated by its year of introduction, which is not necessarily the same as the production year for the vehicle. Vehicle production often covered several years and but might use only one (older) specification of armour plate that had already been milled and stockpiled. The year when the armour plate was milled could often be several months, or even a year or more, before it is assembled into the vehicle. When there was a change in armour hardness specifications midway through vehicle production, it is quite possible and even likely that consecutive vehicles were produced with differently specified armour, simply because each was assembled from the armour plate that was available at the factory.

When additional armour is applied over a surface, the thickness of each plate should be used when determining the individual BHN, not the total thickness of the armour.

The Hardness Data tables for gun target plate also includes the definition of penetration for that country.

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Copyright © 1999 David Michael Honner. E-mail: GvA@wargamer.org.