HEAT projectile designs and amount of explosive

I have a question about HEAT projectiles, I know that HEAT projectiles improved their penetration over the years using less explosive charge, but I would like to know if projectiles with more explosive charge would cause more internal damage.
For example, the 150mm HEAT pierces only 61mm with 8.6kg of explosive.

On the other hand, the 105mm HEAT projectile pierces 400mm using 1.27kg of explosive.

The difference in explosive charges is enormous, so the 150mm HEAT, despite piercing much less, shouldn’t the explosive charge cause much more critical damage?

You are looking at the I.Gr. 38 which is an HE shell, the I.Gr. 39 HL/A is Heat HL > Hohlladung > Hollow charge.
And even that is wrong as it should have 200mm/30° when fired from the s.I.G 33, StuH 43 and s.F.H 13 L/17. As they have less velocity with less rotation than the s.F.H. 18 L/30. And multiple develompental factors add to the penetration. Early german Heat rounds used a steel liner, the /C used Zink, generally copper is the best to use. Rotational force is bad for the penetration, dor that reason free rotating driving bands for rifeled barrles and Heat-FS was developed, the germans also had Heat-FS, the Gr. 38 HL/C-KLW.

There were some other nice pictures, which i cant find again currently, well its mostly a overall 7 kg Heat shell with a big cast fin deploy end. With higher velocity and penetration.

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Ok, I took the wrong photo, I wanted to put the photo of the HEAT of the 150mm cannon. Then I will change the photo hehe.
Also thanks for the response, couldn’t a report be made on this 150mm projectile?
PD:Okay, I found that you had already made a report.


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I would like to point out that the penetration of these weapons is meant to be able to engage targets that would’ve been otherwise immune to the long 88mm gun firing APCBC shells. It can pen at most about 220-230mm/0°, so these are meant to supplant it and be able to defeat at least 240mm/30° at most combat range (as is the case of HEAT shells here, all combat ranges)

I have a question, for example, a 100mm flat plate is penetrated by a HEAT-FS bullet from the leopard 1 that penetrates 400mm using 1.27kg of explosive, and then the same plate is penetrated by the HEAT from the brummbar that penetrates 185mm with 5 ,32kg of explosives, which of the two would cause more internal damage? I say this because of the great difference in explosives, the 105 is much more modern so the penetration is optimized and does not need as much quantity, but the 150 with so much explosive It won’t be some kind of sacrifice of penetration for damage,or since the HEAT of 150 is an old model, the explosive dissipates without causing damage.
That’s my doubt.

Bruh. I have no idea. I know that the amount of damage inflicted behind the armour by a fin stabilized HEAT shell is directly related to it’s leftover penetration, if that helps.

Of course, I understand that HEAT projectiles are considered very lethal if they have at least 100mm of penetration left over, from there and descending they lose damage, but I am curious to know where that energy of the old HEAT goes with so many kg of explosive .

It goes the same place all explosions go - in every other direction.

and since the explosion takes place outside the armour, if the explosion itself doesn’t breach the armour then it does no damage inside.

There is a common misperception that HEAT explosions ONLY explode in the direction of the penetrating slug. This is not true - the explosion of a HEAT projectile goes in all directions just like every other explosion.

However a small part of it is focused by the cone into the more-or-less linear slug - but only that part that is exploding in the direction of the cone in the first place.

Now explosives do have some directionality - they proceed outwards from the point of initiation, and you get more effect in that direction than all the other directions… but there is still an explosion in all those other directions too.

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Thanks for the reply.
So it seems that the damage of HEAT against very light vehicles is not well modeled, since you shoot against those light vehicles with only 10mm of armor and the damage is typical of a HEAT, forward damage with little or no spalling.

Yes you’d probably expect significant general blast damage from a big HEAT round vs light armour, but perhaps less than you think -0 even relatively thin armour is quite resistant to blast, with 20-30mm being considered adequate even these days.

See also the tests on the experimental spaced armor on a Conqueror at https://apps.dtic.mil/sti/pdfs/ADA474293.pdf - the relatively large DART HEAT rounds did some damage externally - blowing off the additional spaced plates they hit, and also sometimes external stowage, but of course these plates were only held in place by 4 or 6 fittings each.

Descriptions of the damage start on page 22,

Dam, i guess the 15 cm Heat was on the toilet when they recived the explosion damage, it has over 5kg, allmost as strong as the Kw2 He grenade, yet is worse than the 128mm He.

5kg is not much at all - if you look at the Conquerer tests the warheads there had 25lbs - 11kg - and more, for the relatively limited blast damage.

People have really rubbish idea of how much blast will do if it is unconstrained - eg on the side of a vehicle as opposed to from a mine under a wheel or track. If there is no enclosure or constraint the blast is relatively easily deflected into empty space.

Yeah, but it still has an even smaller blast than the 3,7 kg 128mm He round.

On the topic of damage of HEAT(FS) shells:


2-143. The Criterion of Shaped Charge Effectiveness must in the final evaluation be its
ability to defeat an armored vehicle —not just
to perforate its armor. The first element to be
considered in the criterion is that of perforation; the second element is damage after a
perforation. Perforation of a tank’s armor is
not the same as perforation of an idealized
target. Much of the target presented by a tank
is irregular and nonhomogeneous in composition, so that predictions of the effect of perforation cannot be made from flat plate data.
Damage does not occur to a tank just because
a perforation of the armored envelope occurs.
The perforation must cause further destruction inside. This damage depends upon where
the perforation occurs and the residual damaging effect of the jet after the perforation.
Other factors such as stand-off, liner material,
and so on, also are involved.
Usually, a tank is destroyed by releasing the
forces that it carries within it. Thus, tank
destruction depends to a great extent on ignition
of the ammunition or fuel. However, other
types of damage reduce tank effectiveness
equally well, depending upon the circumstances
of combat. For instance, if a tank is immobilized during a retreat, it is lost just as surely
as though it had been burned. In the case of an
attacking force, if the firepower of the tank is
destroyed, the tank is no longer of use in the
particular action.


" Diesel fuel is not nearly so easily ignitable as
gasoline. Rounds with a large residual penetration have an appreciably better chance of igniting diesel fuel. Another effect in the diesel
fuel firings is produced by container size. In
the firings of the 3.5-in. rockets, small containers containing five gallons of diesel fuel
were not ignited in 13 attempts.
Exactly what constitutes “sufficient residual
penetration” cannot yet be specified. The
amount of damaging power left in a shaped
charge jet after a target perforation that is
necessary to do damage will vary, depending
on the point cf entry into the tank. If “residual
penetration” is acceptable as an index, the
range of values that can be selected is probably
greater than 1 in. and less than 3 in., to do the
type of damage that is confined to a narrow path
behind the perforation. A figure frequently used
is 2.5-in. residual penetration.
The damage from shaped charges using liner
materials other than copper is somewhat different. Materials such as steel or aluminum
tend to cause more fragments to fly off the
rear face of the armor, and thus fragment damage is more widespread than damage from
copper cones. However, neither steel nor
aluminum lined cones have as great a penetration as copper cones of the same diameter.
Both steel and aluminum cone-shaped charges
produce considerable pressure effects inside a
tank upon perforation. The pressure from
aluminum cones is apparently somewhat greater
than from steel. Tests on animals placed in a
tank fired on by a 5-in. shaped charge showed
them to be unharmed unless hit by fragments.
The approximate pressure measured by paper
blast gages was of the order of 50 psi. This
pressure did, however, tear off hatch doors
and bend bulkheads within the tank.

You can read more here:https://apps.dtic.mil/sti/pdfs/AD0389304.pdf
around page 90

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