Early HEAT Ammunition

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Yoozername
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Re: Early HEAT Ammunition

#46

Post by Yoozername » 29 Oct 2016, 02:28

I am not so sure we discussed the KWK37 though.

The basic issue I have is that many reports state that 600 meters is the maximum range that HL/X ammunition was to be used. Beyond that it becomes bombardment. The 'training' data seems to contradict that. Given the high 90s % at 1000m, it would actually be a range that the weapon could effectively shoot armor.

The main difference is that the HL version is shorter and possibly more balanced. The HL was also used in the German IG 18.

I suspect that the sights used the HE marks for aiming. I don't believe any sights had HEAT graduations.

I believe we discussed this...it is one of the Soviet infantry guns the Germans produced HL/B and HL/C for...Treffer means hit, and it claims 3 out of 10 for 1000 meters. I would assume that means that they know the range...

Image

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Re: Early HEAT Ammunition

#47

Post by Yoozername » 29 Oct 2016, 03:05

I don't know internal ballistics, but I do know 100% of the energy from the charge is not transferred to the projectile. In which case the energy in the spin may be not exactly equal to the energy missing from the projectile's muzzle velocity.
The spin is directly related to the translational velocity. That is why howitzers and guns that vary the charge are actually varying the muzzle velocity as well as the rotational velocity.

Speaking of charges, the KWK37, Pak40, and KWK40s have very similarly sized powder weights for the HL ammunitions. The longer barreled weapons have multiple equivalent types but the shorter L24 seems to use one type. More than likely a faster burning propellant.


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Re: Early HEAT Ammunition

#48

Post by Yoozername » 29 Oct 2016, 23:44

Yoozername wrote:The usual suspects...

Image

The design progression shows the conical shape giving way to the rounder half-spherical liner, the better standoff , the better materials (zinc), improved 'spit-back'.

I am told that the above are actually the German 10 cm (105mm) HEAT rounds.

These below are cutaways of the 7,5 cm HL/X series, A,B,C left to right.
HEAT75.jpg
HEAT75.jpg (88.33 KiB) Viewed 2035 times
Last edited by Yoozername on 30 Oct 2016, 04:14, edited 2 times in total.

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Re: Early HEAT Ammunition

#49

Post by Mobius » 30 Oct 2016, 02:37

Yoozername wrote: Image
Unless you have an account at ww2ammo you can't see the image.

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BDV
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Re: Early HEAT Ammunition

#50

Post by BDV » 01 Nov 2016, 17:28

So to sum it up, no outrageous deficiencies, a passable (although inferior to available 50 mm kwk fired projectiles) option for AT; overall making the 75L24 an underwhelming but reasonable option for MBT weapon in 1941.
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Re: Early HEAT Ammunition

#51

Post by Yoozername » 01 Nov 2016, 19:10

BDV wrote:Hello

How effective were the early forms of HEAT ammunition in combat, for both Germans (75 mm L24 gun) and the Italians (the "effeto pronto" for the 47mm gun); 1941-42?

German work on putting bigger, longer guns on tanks suggest that they were not impressed with the results, but they may have had other reasons.
To sum it up, given this OP, the first HEAT round, the HL, was not very good and the second one, the Hl/A was a big improvement but had issues with accuracy at anything but short or medium range.

I doubt the 47mm weapon was effective against anything but the lightest armor.

Germans put on longer guns because they were up against longer guns. They developed better Hl/B and Hl/C as an economical way for short barrel weapons to have some chance, and to have an economical means of mass producing a dual purpose round for longer barrels.

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Re: Early HEAT Ammunition

#52

Post by Kawinksy » 04 Nov 2016, 17:23

Very interesting topic, admire your knowledge Yoozername.

What does "Treffer auf 10 Schu? " means? Thanks!

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Re: Early HEAT Ammunition

#53

Post by Stiltzkin » 04 Nov 2016, 19:37

What does "Treffer auf 10 Schu? " means? Thanks!
Amount of hits per 10 shots, "hits per 10 shots"?

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Re: Early HEAT Ammunition

#54

Post by Yoozername » 11 Nov 2016, 21:15

Kawinksy wrote:Very interesting topic, admire your knowledge Yoozername.

What does "Treffer auf 10 Schu? " means? Thanks!
Thanks, I have probably been fascinated by this stuff close to half a century...

"Treffer auf 10 Schu? " gives a rough percentage estimate for 10 shots, so 3 for 10 @ 1000 meters is 30%. The big IF is IF you know the range (called training sometimes). At 1000 meters, range estimation factors in heavily. Especially for lower velocity or unstable flight characteristics. In real world terms, you are really needing to know the range. Not impossible for a defensive position that would have access to accurate maps and an optical range finder. But still, I would wait till they were closer. Look at the enemy tanks in the foldout, they suggest hitting certain areas, nice advice but given the spread, I doubt that anything over a 100 meters is just kidding themselves. I would assume that the German IG would have similar performance. I believe I read that they only had a drill with three settings. That is, dial in a range and either aim at the bottom of the tank, the center, or the top. Real cannon-balling IMO.

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Re: Early HEAT Ammunition

#55

Post by Kawinksy » 16 Nov 2016, 15:33

Yoozername wrote: Thanks, I have probably been fascinated by this stuff close to half a century...
Wow, that's impressive! Looking forward to more extensive / helpful post from you in the near future. :D
Yoozername wrote:"Treffer auf 10 Schu? " gives a rough percentage estimate for 10 shots, so 3 for 10 @ 1000 meters is 30%. The big IF is IF you know the range (called training sometimes). At 1000 meters, range estimation factors in heavily. Especially for lower velocity or unstable flight characteristics. In real world terms, you are really needing to know the range. Not impossible for a defensive position that would have access to accurate maps and an optical range finder. But still, I would wait till they were closer. Look at the enemy tanks in the foldout, they suggest hitting certain areas, nice advice but given the spread, I doubt that anything over a 100 meters is just kidding themselves. I would assume that the German IG would have similar performance. I believe I read that they only had a drill with three settings. That is, dial in a range and either aim at the bottom of the tank, the center, or the top. Real cannon-balling IMO.
Just to get it right, I have some more questions if you don't mind.

With 10 fired shots on a target at 1000 metres, one could have a hit probability of about 3 or 33% in training with ideal circumstances?
What you mean by unstable flight characteristics? A wider dispersion pattern or arbitrary parabolic trajectories in particular for the Gr.38 Hl? What would be interesting to know, if the given hit probability actually only relates to certain areas on the tank as marked in the pamphlet, or does it indicate the general probability to hit a target at ranges of 1000 metres? I think thats a big difference and might explain the low probability for a hit. But then again, that's up to ones interpretation and I'm unsure how to view it. Thanks though.

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Re: Early HEAT Ammunition

#56

Post by Mobius » 16 Nov 2016, 16:15

Kawinksy wrote:
Yoozername wrote: Thanks, I have probably been fascinated by this stuff close to half a century...
Wow, that's impressive! Looking forward to more extensive / helpful post from you in the near future. :D

Just to get it right, I have some more questions if you don't mind.

With 10 fired shots on a target at 1000 metres, one could have a hit probability of about 3 or 33% in training with ideal circumstances?
What you mean by unstable flight characteristics? A wider dispersion pattern or arbitrary parabolic trajectories in particular for the Gr.38 Hl? What would be interesting to know, if the given hit probability actually only relates to certain areas on the tank as marked in the pamphlet, or does it indicate the general probability to hit a target at ranges of 1000 metres? I think thats a big difference and might explain the low probability for a hit. But then again, that's up to ones interpretation and I'm unsure how to view it. Thanks though.
That's a good question. Is the 30% chance at 1000 meters of hit based on dispersion alone? Is the target one of the selected tanks or is it the German standard target of 2m x 2.5m? Or is it the shaded area?

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Re: Early HEAT Ammunition

#57

Post by Yoozername » 16 Nov 2016, 19:16

Kawinksy wrote:
Just to get it right, I have some more questions if you don't mind.

With 10 fired shots on a target at 1000 metres, one could have a hit probability of about 3 or 33% in training with ideal circumstances?
What you mean by unstable flight characteristics? A wider dispersion pattern or arbitrary parabolic trajectories in particular for the Gr.38 Hl? What would be interesting to know, if the given hit probability actually only relates to certain areas on the tank as marked in the pamphlet, or does it indicate the general probability to hit a target at ranges of 1000 metres? I think thats a big difference and might explain the low probability for a hit. But then again, that's up to ones interpretation and I'm unsure how to view it. Thanks though.
Well, it's actually 30%...

Yes, these are unstable due to the internal void (hollow) and very large mass to the rear for the HL rounds. Compare with the Panzerworld link earlier in the thread also.

As far as the areas of the tanks, look closely and it actually calls out three areas, black, hatched and white. Basically meaning black is a good hit, hatch means some effect and white is NG. They are all different is area, so I would hazard a guess that they mean the the basic 2mx2.5m target. Note, that makes it even more unlikely. That is, you must know the range, AND get a hit (30%), AND it must strike a good area. Basically, it is not worth it.

The Germans typically state 600 meters in documents as being a reasonable range to open fire and expect a hit with a acceptable number of rounds.

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Re: Early HEAT Ammunition

#58

Post by Mobius » 16 Nov 2016, 20:33

Re-reading the thread the 30% at 1000m figure of the 76.2mm HL/C seems to be at odds with the Training data of 75mm HL/C. I would of thought they would be pretty close.

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Re: Early HEAT Ammunition

#59

Post by Yoozername » 16 Nov 2016, 20:39

The 76.2mm 290 (r) looks like this...I doubt they could hunt down many T34s....Its muzzle velocity was around 300 M/s

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Re: Early HEAT Ammunition

#60

Post by Yoozername » 16 Nov 2016, 20:46

Here is 88mm Tiger HEAT data

Hl.39 (HEAT)[edit]
Type: high explosive anti-tank (HEAT) round with a shaped charge.
Projectile weight: 7.65 kg (16.9 lb)
Muzzle velocity: 600 m/s (2,000 ft/s)
Penetration figures given for an armoured plate 30 degrees from vertical
Hit probability versus
2.5 x 2m target [2]
Range Penetration 1 2
100 m 90 mm 100% 100%
500 m 90 mm 100% 98%
1000 m 90 mm 94% 62%
1500 m 90 mm 72% 34%
2000 m 90 mm 52% 20%

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