Shells and projectiles (Advanced level)

[Moon]

As with the other posts here, the following text is a translation of the materials posted on the Russian developer site. (some of this info is also in the game manual)

Types of shells

The majority of different shell types of the Second World War period were reconstructed in the game.

AP (armour-piercing)

A solid (does not contain any explosive charge) armor-piercing shell with a shaped nose, sometimes with a ballistic cap. After armor penetration damage is inflicted in the following way: the fuse detonates the charge which shatters the case and scatters hot, sharp fragments of projectile case and armor (shrapnel) at high velocity. Shells of this type were easy to produce, reliable and had rather high penetration ability. They were especially effective against homogeneous armor. But there were also some drawbacks in comparison with APHE (which had an explosive inside): low interior effect, ricochets against inclined armor and low efficiency against case-hardened and cemented armor. This type of shell was used frequently during the Second World War. Mainly small-caliber automatic guns were equipped with it. AP shells were common in the British Army, especially in the first period of war.

APHE (armor piercing high explosive)

A sharp-nosed armor-piercing projectile. Very similar to the AP shell, but equipped with tail chamber filled with explosives in form of TNT or a fire-bar element and a tail fuse. After armor penetration the shell explodes, damaging the crew and tank gear. In general this projectile retained most of the advantages and disadvantages of AP shells, the difference was its significantly improved interior effect and weaker piercing action (owing to the smaller mass and shell hardness). Moreover, the tail fuses were poorly developed at that time, which sometimes caused shells to explode too early even before actually hitting the target. Sometimes the fuse simply failed to explode after penetration. When the shell hit soil it usually didn`t explode at all. APHE were very often used in heavy artillery, as its relatively heavy weight could compensate for its disadvantages. Light artillery systems were also equipped with APHE due the low production cost and simple production method. Soviet, German, Polish and French artillery systems used this type of projectile.

APBС (armor piercing projectile with a blunt nose and a ballistic cap)

A solid (with no explosive) flat armor-piercing type of shell with a ballistic cap. This type of shell was specially designed to burst strong case-hardened and cemented armor. It destroyed the highly fragile case-hardened armor layer with its capped nose. Among other positive features of these shells were their good efficiency against moderately inclined armor. They were technologically easy to produce. The drawbacks of APBCs were their lower effect against homogeneous armor and excessive “normalization” rates (accompanied by shell destruction) when hitting heavily inclined armor. Moreover this type of shell didn`t have any charge filling which lowered the efficiency of the penetration. Solid blunt-nosed AP projectiles were used only by the USSR from the middle of WW2 on.

APHEBC (armor piercing high explosive projectile with a blunt nose and a ballistic cap)

An armor-piercing shell with a blunt nose and explosive filling. It is similar to APBC. The main difference is a special tail chamber containing a charge filling and a tail fuse. It had similar advantages and disadvantages as APBC, with the improvement that the shell exploded inside the target after armor penetration. Practically it was a blunt-nosed APHE shell. APHEBC were used only by the USSR as the basic type of armor-piercing shells during the whole wartime period. At the beginning of war the Germans were using relatively thin cemented armor and thus APHEBCs` efficiency was satisfactory. In 1943 the Germans implemented thick homogeneous armor and the efficiency of APHEBCs dropped. Consequently at the end of the wart the Soviets developed and passed into service new sharp-nosed shells.

APC (armor piercing capped)

A sharp-nosed shell with an anti-armor cap and usually with explosive filling. Basically it’s an APHE shell equipped with a flat anti-armor cap. Thus it combined the best features of sharp-nosed and flat shells: flat cap prevented it from bouncing if it hit inclined armor and slightly “normalized” the shell, effectively destroying the case-hardened layer of armor; it also protected the shell nose. APC was effective against homogeneous, case-hardened and inclined armor. The drawback of this type of shells was that its flat cap decreased the shell aerodynamics, thus decreasing accuracy, and reduced velocity and penetration rates at long distances especially when heavy caliber shells were used. Therefore the use of these shells was restricted to small-caliber guns; APCs were included in the ammo of 50mm German anti-tank and tank guns.

APCBC (armor piercing capped ballistic capped)

Sharp-nosed armour piercing - capped shell with a ballistic cap. It usually had an explosive filling and a tail fuse. However, the British Army sometimes used solid projectiles of this type. Generally, it was an APC shell equipped with a ballistic cap. This cap drastically increased the shell aerodynamics. When the target was hit, the cap wrinkled easily and thus didn`t influence at all the armor piercing capability of the shell. Due to their high efficiency against plate-armor of different types and slope angles APCBC were the top performers of AP shells during World War II, APCBCs were widespread in the armies of the USA, Germany, and Great Britain since 1942-43. They practically replaced all other types of armor piercing shells. On the other side their drawbacks were a complex manufacturing process and high cost. That`s why the Soviet Union failed to set up line production of this type of shell.

APCR (armor piercing composite rigid)

The APCR (sub-caliber) projectile had a complex structure. It included two parts: an armor-piercing core of high-density material such as tungsten carbide and a sabot of a lighter material (e.g. an aluminium alloy). When a shell hit a target, the sabot was shaved off and the harder penetrating core pierced the armor. The shell was not equipped with a charge filling. The target was damaged by core shrapnel and hot armor frags. The weight of the APCR projectiles was considerably lighter in comparison to standard AP shots; the lighter weight allowed rather high muzzle velocities. The use of composite shells improved the armor penetrating abilities of existing guns. The usage of APCR enabled even older guns to destroy advanced military hardware. At the same time composite shells had some drawbacks. Their shape resembled a coil (although there were some shells with a streamlined form, bzt they were rather rare) and it decreased shell aerodynamics. These light shells lost their speed very quickly. This had an influence on armor-piercing performance at long distances, which could be even worse than that of standard armor-piercing shells.

Sub-caliber shells had poor efficiency against inclined armor as the hard, but nevertheless fragile penetrating core was easily broken by the bending stresses. The interior effect of these shells was lower than that of AP caliber shells. Small-caliber composite shells were ineffective against armored targets with skirt armor. APCRs were expensive and complicated to manufacture. Besides, the deficit of tungsten hindered the production of shells. Consequently the amount of APCR used during the war was relatively low. It was allowed to use them only against heavily-armoured targets and at short distances. German troops were the first to use small numbers of composite shells during the French Campaign in 1940. When the Germans faced heavily armored Soviet tanks in 1941, they brought sub-caliber shells into use at large scale. It considerably improved armor-defeating performance of their tanks and artillery. However the shortage of tungsten metal made the Germans cut down the production of APCBC. Finally, the manufacturing of composite shells was stopped in 1944. Most of the shells that were produced during the war were of small caliber (37-50mm). Trying to duck the tungsten issue the Germans produced Pzgr. 40 © shells with steel penetrating rods and Pzgr.40 (W) – APCR with sabots, but without cores.

In the USSR the mass production of APCR started in early 1943. Soviet shells of 45mm caliber were based on captured German models. Tungsten deficit set a limit on APCR production. The troops received APCR shells only if there was a tank attack threat. The authorities in command demanded reports on each APCR shell used in combat. Composite shells were also used by Allied troops during the second half of World War II.

APDS (armor piercing discarding sabot)

A composite shell with discarding sabot. Once outside the barrel, the sabot was discarded by aerodynamic effect. The remaining shell core without the discarded sabot had very good aerodynamic characteristics and was able to retain high armor-piercing abilities at large distances. Its performance resembled that of AP shells, but its velocity was much higher. APDS shells had the best armor-piercing capabilities, but were very expensive and difficult to produce. The British Army employed APDS since late 1944. Upgraded shells of this type are still in the inventory of various military forces.

HEAT (high explosive anti-tank)

A hollow charge projectile. This armor-piercing projectile functions in a different way than ballistic ammunition (i.e. standard armor-piercing and composite shells). A hollow charge projectile consists of a thin-walled steel shell filled with powerful hexogen explosive or a TNT-hexogen mixture. There is a cup-shaped hole on the front of the projectile with a metal (usually copper) coating. It is equipped with a sensitive nose fuse. When it hits the armor, the charge explodes. The metal on the shell melts and becomes a jet bursting forward at a very high speed. The interior effect is ensured by this cumulative jet and by metal fragments. The penetration ability of this shell does not depend on the speed of the projectile and is the same at all distances. HEAT shells are relatively simple in production, as no advanced metals are required. Hollow charge projectiles can be used against infantry and against artillery as HE frag shells. During the war HEAT shells had many disadvantages. Production technology wasn`t tried-and-true and as result, penetration rates were relatively low (meeting standard penetration rates for this shell caliber or a little higher) and unstable. Shell rotation (wobble) at high muzzle velocities prevented the cumulative jet from bursting effectively. As a result HEAT shells had low muzzle velocity and were inaccurate at anything but short distances due to the aerodynamically non-optimal nose cone. Additionally the detonation fuse of HEAT shells was very difficult to manufacture, as it had to be highly sensitive for the shell to explode quickly enough and yet reliable to prevent the shell from exploding in the barrel (Soviets Union managed to develop an effective detonating fuse of this kind only in late 1944). Mass production of HEAT shells demanded high production volumes of hexogen. Hollow charge projectiles were most used by the German Army. They used this type of shell for their 75mm guns in summer and autumn of 1941. Soviet HEAT shells were based on captured German models. Hollow charge projectiles were included in the ammunition of 75mm guns and howitzers. However their muzzle velocity was relatively low. The Allies equipped for mainly heavy howitzers with HEAT shells. The use of HEAT shells in the Second World War was rather limited (in distinction from nowadays when hollow charge projectiles form the basis of tank ammunition inventories). They were in effect a self-defense means of guns with low muzzle velocity and low armor piercing abilities with custom shells against advancing tanks (regiment guns and howitzers). At the same time all combatants implemented various hollow charge projectiles, such as grenade launchers, aerial bombs and hand grenades.

HE (high explosive)

HE fragmentation shell. They have a hard thin-walled steel or semisteel case filled with and explosive charge (usually TNT or ammonium-nitrate) and a nose fuse. In distinction from armor piercing shells, fragmentation shells weren`t equipped with tracers. When a shell hit the target, it exploded, damaging the target with shrapnel and a blast wave. There were two types of effect: instantaneous fragmentation effect and delayed mining effect (which let the projectile dig itself into soil). HE were mainly used against infantry in cover and in the open, artillery, fortifications (trenches, pill-boxes), and unarmored or weakly armored vehicles. Heavy armored tanks and SP guns are well-protected against HE shells. But heavy HE shells may destroy thin-armored vehicles and damage heavy armored tanks causing armor plates to break, block tank turrets, disable exterior equipment, and may also inflict concussion wounds and injuries on the crew.

[ May 08, 2007, 01:57 AM: Message edited by: Moon ]

[Tofke]

WAOU! mega over hyper interesting.

thx Moon.

Tofke

Beer killer

[Vern_S]

Very good read... Thx Moon...

[pwncake]

tnx Moon for this one and the others nice reading.

You can learn something from it.

[messenger3]

true thanks!

[War RaVeN]

Intresting, very intresting!

[flintlock]

Great stuff! Thanks for this, Moon.

[MikoyanPT]

Nice to know the tools of the trade.

Thanks.

[longbore]

Good stuff!

[Huegel]

Excellent read... thanks a lot!

[Sivodsi]

Good read!

I'm a bit confused about the writeup for AP:

AP (armour-piercing)

A solid (does not contain any explosive charge) armor-piercing shell with a shaped nose...

This is contradicted just a couple of lines below:

...damage is inflicted in the following way: the fuse detonates the charge ...

Is the first line supposed to read "contains little or no explosive charge"?

Sorry for nitpicking!

[Sneaksie]

Wrong translation, in original it reads:

"After armor penetration damage is inflicted by hot fragments of shattered shell and armor, which damage inner components of the vehicle and it's crew."

[Sivodsi]

Thanks!

So AP never contains an explosive charge, right?

[Sneaksie]

Yes, plain AP (not APHE or similar) is a solid shell.

[Kamui]

I would like to make some additions here. I`ve been gathering historic data on WW2 now for some years and in my experience there are oftenly biased explanations favoring certain sides (russian, american, german) etc.

In example, when searching for penetration data on several websites you might oftenly find conflicting numbers or incorrect designations. These are partly from bad translations flaws in researching or propaganda.

Regarding soviet APBC & APBC/HE Shells

On website http://www.battlefield.ru/content/category/10/44/64/lang,en/ you can find similar information as in topic.

1.) An Armor-Piercing High Explosive projectile with a sharp nose (APHE);

2.) An Armor-Piercing High Explosive projectile with a blunt nose and a ballistic cap (APHEBC);

3.) A Solid Armor-Piercing projectile with a blunt nose and a ballistic cap (APBC);

4.) A Solid Armor-Piercing projectile with a blunt caped and a ballistic cap (APCBC).

Armour Piercing with Ballistic Cap (APBC). An AP projectile with a truncated nose (as if the end had been sawn off) covered by a light weight ballistic cap to improve flight characteristics. The truncated nose has better penetration above certain velocities, particularly when it overmatches the target armour plate and when the plate is prone to brittle failure. This was a common projectile for the USSR in World War Two as they did not use APC projectiles until the 1950s.

The information on developer site about APBC stating

...This type of shell was specially designed to burst strong case-hardened and cemented armor. It destroyed the highly fragile case-hardened armor layer with its capped nose...

is definetely wrong. The USSR developed blunt nose projectiles which proved better against inclined armor then sharp tip shells, but they had no effect on german face hardened armor.

For references see website http://www.freeweb.hu/gva/weapons/introduction.html#Face_Hardened_Armour

Face hardening (FH) is a method used to increase the armour hardness of the surface of armour plate. The rear side of the armour plate remains at its original hardness. Face hardening is carried out by taking a slab of RHA and heat treating it again, but on one side only. The heat treating is time consuming and results in a warped plate which must then be flattened in large presses. The Germans were able to handle plates up to and including 50mm thickness (with production oversizes up to 55mm), and tried 80mm FH on the early Panther glacis. Later on the Germans found a way to use a heavy electrical current flow through the steel to induction-harden one face. Both methods were used until the end of the war.

The purpose of the hardened face is to shatter an incoming projectile’s head before it can penetrate. The Germans found it resisted Soviet uncapped AP and APBC projectiles quite well, when the armour plate thickness was around the same size or not too badly overmatched by the projectile (such as Pz.Kpfw.IV 50mm front armour vs. Soviet 45mm or even 76mm AP or APBC). Britain and the USA tested projectiles against FH armour as a matter of course until about 1943, but rarely used it on production vehicles because of its relatively poor resistance to German APCBC in comparison to RHA. The Germans were faced with APC and APCBC from the Western allies only, not the Soviets, so their decision to use FH armour weakened their tanks against Western guns but strengthened them against Soviet guns.

Regarding AP/HE projectiles or fillers

Armor Piercing ammunition had been developed originally in late 19th century against armored ships. For such targets it was not enough to just make a hole here or there but also to cause internal damage. Same principle is for tanks which is called "after armor effect". A good example would be the german Mauser Tankgewehr in WW1, which was able to penetrate the armoring of british or french tanks but didn`t necessarily cause the vehicle to stop, so crews had been ordered to aim for the places where internal fuel tanks are located.

Nations as Russia, Germany, Italy and Japan used mostly AP/HE and other projectiles with filler to cause an explosion inside the target after the armor had been penetrated. Especially german ammunition had been successfull on that terms against M4 Sherman which was sometimes referred as "Ronson lighter" or "Tommy cooker".

Britain didn`t made use of AP/HE ammunition in WW2 for they believed this type of ammo would be unreliable and also has lower penetration abilities. The USA developed AP/HE ammunition for their 75mm and 76,2mm guns, however due to bad quality of their primers it oftenly lead to failure. When the british received lend lease shermans and 75mm guns, they removed the explosive fillers from american ammunition.

http://www.freeweb.hu/gva/weapons/britain.html#Explosive_Filler_in_Armour_Piercing_Projectiles

No British AP or APCBC projectiles had an explosive filler in the warhead. Even when the British used USA projectiles for the 75mm gun, such as the M61, they removed the HE filler. In the Churchill Service Instruction Book, it is described as M61 Shot, with the diagram showing that the fuse found in the USA projectile was replaced by a plug holding only the tracer.

The words “shot” and “shell” have two distinct meanings in English and are often used loosely which can result in some confusion. “Shot” is a contraction of roundshot and harks back to the early days of artillery; it implies a solid projectile with no internal cavity. “Shell” on the other hand is used to describe a projectile with an internal cavity, which may be used to contain HE, smoke, shrapnel, etc.

[John Kettler]

Everyone,

This is a must read item, the almost unknown U.S. Test No. 1. This particularly concerns spaced armor (e.g., late model Panzer III) effects (disastrous) on the M61 APC projectile. The site also provides priceless side by comparisons of that with the British version, which was called M61 Shot by them. As groggy as it gets! From the link (Fair Use)

http://wargaming.info/armour05.htm

ETOUSA OUTGOING MESSAGE

ORIGINATOR: ETOUSA.

DATE: 24 May 1944.

ACTION TO: AGWAR.

INFO TO: CG AGF.

TEXT: Recent firing tests indicate twenty mm homo plate spaced six inches from fifty mm FH plate at thirty degree obliquity will defeat service velocity seventy-five mm APC M sixty-one at five hundred yards by functioning base fuze.

(signed Eisenhower)

Also tests witnessed indicated instantaneous functioning of HE filling in ninety mm APC M eighty-two does not permit satisfactory armor penetration performance on one hundred mm homo plate at thirty degrees at five hundred yards.

(Reference ETOUSA cable WL dash two one nine two and British ordnance board proceding number two six five nine four)

If tests in US indicate above deficiencies cannot be corrected immediately it is requested all seventy-five mm seventy-six mm and ninety mm APC shipped for ETO be inert loaded.

DISTRIBUTION: Ord O, G-3, G-4, FUSAG, SHAEF.

ORIGINATING DIVISION: AFV&W Section.

PRECEDENCE: Routine.

NAME & RANK: W. J. Reardon, Col, Cav, 1039.

Regards,

John Kettler

[John Kettler]

Am absolutely astonished no one has responded to the stunning info I posted. At the very least, I expected to see Moon chime in.

Regards,

John Kettler

[Kamui]

It's been a time since I've last took a look into the Forum. But now, WOW! I could imagine some flaws in US fuzes, but didn't know it was that drastic!

It's ridiculous, for I remember in WW1 German naval ammunition proved more reliable then british rounds, therefore i thought they confiscated them and research primers and fuzes for copying.

[rune]

Kamui,

Never make assumptions based on a freeweb site. The British did make and use APHE for the 2lber in fighting in Africa. Tests were conducted after Beda Fomm by 2nd R.T.R. and the shell was used.

Source: Thomas Jentz, "Tank Combat in North Africa"

Just found a web site that has a photo of the round and also quotes jentz.

http://208.84.116.223/forums/lofiversion/index.php/t19833.html

Rune

[Kamui]

Hi Rune,

for researches and gathering infos from websites, I always try to compare several of them for accordance. From what I read up to now, I got the idea that the british only used solid shots and had an HE shell for the 2pdr, which wasn't used in service. However, after your direction i checked again and found corresponding info:

The 2 pdr was originally armed with AP Shell (an armour piercing round with an explosive filler), the design of this round was asked for in September 1934 and provided by January 1936 - these rounds were filled with Lyddite. In 1938 it was decided to provided a projectile with better penetration performance, the first AP Shot was asked for in 1938. Interim steps involved inert filling of stocks of empty AP shell.

http://www.wwiiequipment.com/index.php?option=com_content&view=article&id=73:2-pounder-anti-tank-gun&catid=40:anti-tank&Itemid=58

I also updated the info on my WW2 Excel Encyclopedia

http://www.angelfire.com/indie/kamuichan/

Thank, Kamui

[rune]

Kamui,

No problem, it is why I had a smiley, a little tongue in cheek humour. Glad to be of help, I remember discussing it with rexford several years ago. The 2lber aphe was used in limited combat, what also surprised me was the British tested an APHE for both the 17lber and the 25lber. Those rounds were never fielded, but at some point there was interest in the type of shell.

Rune

[Kamui]

Hi again rune,

no prob about that mate. I assume they dropped the APHE shells in favor of AP shots due to problems with fuzes and penetration had priority over destruction power. For me it stays mysterious, same as the non usage of penetration caps on japanese APHE shells.