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.50 / 20mm as AT


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I hope someone can explain me that - I confess that I really don't know if it's realistic or not.

I often see light armored vehicels killed by relativ small calibers like the .50 or 20mm.

For example - Hellcats, cause I have seen this last. A Hellcat got a front turret penetration by a 20mm gun (distance ~250 meters). The Hellcat was knocket out. Why this? How much damage can be done by even several hits of this caliber - assuming that each shot of a salvo hits and is a perfect penetration? I would understand that it can damage the gun and kill the gunner/commander, or hit the engine (or the driver) and make it immobile. But a single salvo, and the whole tank is kaput - isn't it a bit overpowered?

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Thin skinned AFV's also often shrug off low caliber hits. But think of it this way:

A .22 bullet is not very likely to penetrate all the way through your car to the passenger compartment, but if you're in a car getting hit by them and one or two do get through, are you staying in there?

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<blockquote>quote:</font><hr>Originally posted by Andrew Hedges:

I think the otherwise forgettable movie Patton explained this best:

Q: Is it true that machine gun bullets can go all the way through our halftracks?

A: No, they just go through one side and then bounce around inside.<hr></blockquote>

you thought "patton" was forgettable? wow...

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<blockquote>quote:</font><hr>Originally posted by Vergeltungswaffe:

Thin skinned AFV's also often shrug off low caliber hits. But think of it this way:

.22 bullet is not very likely to penetrate all the way through your car to the passenger compartment, but if you're in a car getting hit by them and one or two do get through, are you staying in there?<hr></blockquote>

You talking about a bailing crew - but the tank was 'Knocked-Out', not 'Abandoned'.

Don't ask me a question I can't answer. I will tell you when someone shoots on me with a .22 while I'm sitting in car ;) . But counter question - if I would leave the car, would this rise my chance to survive? I had a better chance if I try to DRIVE away as fast as possible!

[ 10-31-2001: Message edited by: Scipio ]</p>

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<blockquote>quote:</font><hr>Originally posted by Maastrictian:

I think the analogy works a bit better if you are in car filled with gasoline and high explosives. Not only should you get out of there, but enough small bullets will hit something flamible.

--Chris<hr></blockquote>

I don't think so. The ammo is not so explosive as you may think, and AFAIK the most tanks don't drive with high inflammable benzin, more with diesel. And BTW, if this would happen ,you could see it.

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If you look at specs for modern light armor they often 'boast' about their ablity to defeat 7.62 ball. Heavy mgs can make Swiss cheeze of these vehicles, especially from the side and rear. For a light tank the little Stuart was actually pretty decently protected!

And how does a thin skinned vehicle shrug off a penetration? Well, a solid shot mg round penetrating an empty M3 halftrack body will just bounce around for awhile (with luck). Something penetrating a Sherman is likely to have enough energy to set off stored gun rounds.

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<blockquote>quote:</font><hr>Originally posted by MikeyD:

And how does a thin skinned vehicle shrug off a penetration? Well, a solid shot mg round penetrating an empty M3 halftrack body will just bounce around for awhile (with luck). Something penetrating a Sherman is likely to have enough energy to set off stored gun rounds.<hr></blockquote>

As I said, the ammo is not so explosive as people believe. You can take a 1000kg barrel of TNT and drop it from an aircraft from 1000 meter or more. It will hit the ground with enough power to walk through a building and disappear a few meters below the cellar. But if the detonator not ignite the TNT, the bomb don't explode. That's the reason why we still find those things in our cities.

Okay, I mean, the 20mm will do some damage and cause casualties, but again - why knock out the whole tank? And this happens often, not sometimes. BTW, I don't speak about HTs, I mean real tanks like the Hellcat.

[ 10-31-2001: Message edited by: Scipio ]</p>

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<blockquote>quote:</font><hr>Originally posted by Scipio:

I don't think so. The ammo is not so explosive as you may think, and AFAIK the most tanks don't drive with high inflammable benzin, more with diesel. And BTW, if this would happen ,you could see it.<hr></blockquote>

Didn't we go round this loop a week or so ago ;)

As for diesel being the predominant fuel, well, I think you may be wrong there. This site lists many of the main tanks from WWII, and includes the fuel they used. Of the vehicles used in Western Europe, most seem to have been petrol fired.

[ 10-31-2001: Message edited by: JonS ]</p>

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<blockquote>quote:</font><hr>Originally posted by Scipio:

... You can take a 1000kg barrel of TNT and drop it from an aircraft from 1000 meter or more. It will hit the ground with enough power to walk through a building and disappear a few meters below the cellar. But if the detonator not ignite the TNT, the bomb don't explode. That's the reason why we still find those things in our cities...<hr></blockquote>

LOL, good point. i wish I'd thought of it when we were discussing how non-fragile ammo is the other week. :cool:

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<blockquote>quote:</font><hr>Originally posted by JonS:

LOL, good point. i wish I'd thought of it when we were discussing how non-fragile ammo is the other week. :cool: <hr></blockquote>

Hehe, I learned the lesson that Phantom teached smile.gif .

Anyway, I won't discuss the ammo issue again. Even if the ammo or the fuel would be ignited by a 2cm, we would see the tank burn or explode.

But when we are already using this analogy - I wonder what in the tank is so vulnerable when it's NOT the ammo - or the crew, cause the crew had left the tank without casualties after the hit. Another riddle for me.

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<blockquote>quote:</font><hr>Originally posted by Scipio:

Hehe, I learned the lesson that Phantom teached smile.gif .

Anyway, I won't discuss the ammo issue again. Even if the ammo or the fuel would be ignited by a 2cm, we would see the tank burn or explode.

But when we are already using this analogy - I wonder what in the tank is so vulnerable when it's NOT the ammo - or the crew, cause the crew had left the tank without casualties after the hit. Another riddle for me.<hr></blockquote>

Rupturing a high pressure hydraulic line for turret traverse really wouldn't make the crew happy. It would also prevent the tank from using it's gun. Germans vehicles were all gas powered and so were the vast majority of Allied vehicles. Ammo certainly does detonate if the propellant is pierced by any size bullet or fragment. Why else would one of the most common ways of destroying a naval mine be by shooting it (from a safe distance) with a rifle?

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Took this off the Russian Battlefield site. Apparently the biggest fear of the IS-2's was fausts and shreks, which also don't make a very big hole:

<blockquote>quote:</font><hr>"Here is a tank with battened down hatches... but the crew is silent. They respond to neither radio nor knock. There is a small hole with a diameter no more than a cent. That was a "faust", that was its work. A shield was torn off, and a next round penetrated the armor...<hr></blockquote>

And this maybe gives a reason why a tank crew may get the hell out of a tank while the going is good:

<blockquote>quote:</font><hr>Those who saw a tank battle knew how terrible death could be for tankers. If a round hit the ammunition or fuel tanks, a tank would be destroyed at once - just blast off and the crew perishing without any torture.

Often a round just penetrates the tank's armor but doesn't hit the ammunition or fuel tanks. All crewmembers are wounded, their tank is burning, but the crew is unable to extinguish the flame. They need to escape the tank and run off to a safe distance. However, the tankers are wounded and they simply can't do that, they can't open the locked hatches. And you can hear the cries of those being burned alive. You can't help them because the hatches are locked inside..."<hr></blockquote>

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Boys, am I talking chinese or what???

If someone shoot on a tank, and the tank explodes, then I CAN ****ING SEE THIS IN THE GAME AND WILL BE HAPPY. But this doesn't happen. The tank is hit by a 2cm and knocked out.

Damage a hydraulic line - okay, 'Gun damaged'.

USTANKER : I know that they are more vulnerable, but that doesn't explain the lethal damage by one hit.

MACHINEMAN - HEAT ammo is something completly different and can't be compared with a 2cm shell, even if both makes only a small hole. And again, the tank is NOT BURNING!!!

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A few things come into play with penetrating and non-penetrating hits.

Penetrating hits:

1. A penetrating hit tends to ricochet around inside a tank and wreak havoc on soft-flesh, controls, and anything else not made of rolled homogenous steel.

2. Ammunition IS flammable. While it might not detonate from a 13,000 foot drop, it will detonate when heat is applied. It's even more volatile with heat AND pressure.

3. Concussion: the effects of a penetration disorient the crew and can cause temporary loss of all bodily function.

4. Fear. Picture this..Your armored vehicle gets hit, shell fragmnts just ricocheted around your tank and decapitated you bow machinegunner. The turret ceases to function, your vision block are cracked, and you can't see squat. Suddenly, the engine cuts out, you smell fuel, and your loader freak out. What now Sergeant?

Non-penetrating hits:

1. Spall: The round does not penetrate, but transfers it's kinetic energy through the armor. the inside of the armor (the part facing you and your crew and a mere 6 inches away from your body) flakes off pieces of steel and zings them throughout the turret and hull. These fragments ricochet of the inside walls of the turret and hull until they lose their force. IN the meantime, crewmen have limbs ripped off or are killed.

2. Exposed crewmen: a non-penetrating hit has a high probability of killing or wounding crewmen with their heads/bodies outside the vehicle (hatches). Even crewmen with just their heads out of hatches can be blinded or killed by fragments.

This doesn't even take into account hits by Panzerfausts or Bazookas or Schrecks, which deliver a molten stream into the inside of a vehicle.

It's no fun being in a vehicle hit by anything, whether it penetrates or not.

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<blockquote>quote:</font><hr>Originally posted by Scipio:

MACHINEMAN - HEAT ammo is something completly different and can't be compared with a 2cm shell, even if both makes only a small hole. And again, the tank is NOT BURNING!!!<hr></blockquote>

I don't know exactly what BTS bases their damage model on, but I'd wager hollow charge type penetration is probably LESS damaging inside the tank than a 50 cal type shell racketing around. What isn't directly in the way of the penetrating jet isn't touched. The big advantage of shrek type weapons is that they can get through heavy armour, not that they can do a lot of damage once inside. A 50 cal shell, on the other hand, is a big hunk of metal going very fast, that would bounce around for a while inside. Who knows what it can damage in the tanks innards without causing it to burn or blow up, but probably plenty. Sure the tank may be able to be recovered and patched, but BTS just models battlefield knockouts.

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Clueless people can't face Scipio's question, and so go on about their nightmares.

Nobody in the crew is a casualty. The tank is not burning. It was only penetrated by 20mm AP - or in some cases, 50 cal AP, which might be enough to occasionally kill people or start fires, but -didn't do either- in this case. A large caliber AP might have smashed a dozen important things without hitting crew or starting a fire. But what is the peashooter supposed to do, if it doesn't hurt the crew or start a fire?

I think he has a valid point, and it is one I have noticed before. It applies to bunkers as well as tanks. The CM penetration model seems to go from "penetrated" to "knocked out" almost all of the time, with only occasional "no significant damage" expections, and those exceptions seem to happen to all types of rounds, regardless of size. In reality, the chance of a total kill with a penetration should be quite low for the smallest weapons, and rise to near certainly only for the largest.

We've all seen the bunker KOed by 37mm AP. The log bunker that is "knocked out" a hundred times more easily than an MG in a wood building. And this issue is only going to get more important, because in Russia there will be penetrations by 14.5mm ATRs, firing semi-auto. Is every rifle round that goes into a tank supposed to destroy it? No. Is it easier to destroy an armor plated halftrack with 50 cal rounds, than its crew standing in the open? No.

Modeling what happens after a penetration needs to be significantly improved. Which needn't mean tracking minutae about every system on the tank. But it does mean something like "roll damage", with "modifiers" for the size of the round, the amount of overpenetration, the defensive qualities of the vehicle (wet stowage e.g.) etc.

Small caliber rounds should have decent chances of causing crew casualties on a successful penetration, and small chances of M-kill (engine damage each) and smaller ones still of knockout and fire. But typically they would either get crew or do nothing. The crew might bail or might not.

Think about it - penetration by a small AP would often not be much worse than spalling, which right now can get a crew member but that is about it. Repeated penetrations might add up - and the crew would probably bail if they lost a second man with no end in sight. But the mysterious perfectly good crew and non-burning tank "KOed" by 12.7mm, 14.5mm, 20mm, or 25mm would go away.

In addition, right now rapidly firing small cannons are overmodeled in almost every respect, because there is too much in the combat system that "multiplies out" completely with an increase in the number of shells fired. 20mm Flak with no chance of penetration can still KO medium tanks with rapid gun and track damage, because these turn on a chance per shot, which does not seem to be reduced for small caliber, but of course remains sensitive to the probability effects of repeat trials, through rate of fire.

The reality is 105mm HE had a hard time damaging a tank track, and the idea that a 20mm AP is going to break one as easily is far fetched. We've all seen 20mm-40mm AA knock down buildings faster than Sherman 105s, which is obviously wrong. Since we know there are some such issues - presumably being corrected for CM2 - Scipio's question is legitimate.

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Let's not forget that the model here stands for "ups, penetration, let's get out of here", not for "kaputt".

Has anyone measured how many penetrations a crack or elite crew takes before it bails out? Maybe the chance is 20% then, compared to lets say 80% for the regular crew we observe every day?

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When a round penetrates, it tends to affect the morale of the crew of an AFV quite severely. If casualties eventuate, they tend to remove their vehicle from the battle. If its likely that the vehicle will brew up, they tend to remove themselves from the vehicle, very quickly.

Only the Japanese and the Russians produced all their tanks powered by diesels, for the obvious power advantage and inflammability of the fuel. The US produced a few diesel powered vehicles but preferred petrol (usually AVGAS as well) powered vehicles.

All AFV's in WWII were very prone to brewing up, some catastrophically, such as the "Ronson" or "Tommy-Cooker" did.

Remember, the tank crews will aim to maximise their survival and so will more than likely abandon their vehicles no matter what the calibre of the round which penetrates, for those very reasons.

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Redwolf, you have missed the point. The tank isn't abandoned - what could be explained with panic etc - the tank is KNOCKED OUT, so it's destroyed, finished, killed, kaput.

JasonC : thank you, that's excactly what I meant. And I totally agree, the damage caused by small arms with high fire rates is generally oversized.

That's the reason why the 3.7AA is such a deadly tankkiller, while it was in reality AFAIK never used as AT weapon. Possibly if nothing else was available, and I assume it wasn't very successfull.

That's why tanks were equipped with BIG calibers, not with small fast firing guns. IMO, this is an very important issue. It is abolutly unrealistic, and in a very important aspect of the game.

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<blockquote>quote:</font><hr>This doesn't even take into account hits by Panzerfausts or Bazookas or Schrecks, which deliver a molten stream into the inside of a vehicle. <hr></blockquote>

Any shaped charge penetration to the cabin is also likely to fill the whole tank with smoke and toxic fumes.

Scipio & JasonC: I agree with most of your points and it matches my suspicion that too many Tank & Vehicle penetrations result in knock outs. While a shot can penetrate & bounce around creating havoc, it can also penetrate and hit nothing and when there are no casualties shown in the game then why do the crews almost always bail out?

On the other hand I also think that multiple hits of 20mm - 37mm rounds should realistically kill light skinned vehicles like the Hellcat just by the fact that the odds of something vital being hit are much higher.

Also in the game when you get "Internal Armor Flaking" results has anyone seen casualties caused from that? I'd expect that casualties from flaking armor should be as heavy as casualties from bounce-around-inside shots, but I don't think I've ever seen casualties from that cause myself.

Gyrene

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