Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: avin on April 08, 2001, 01:29:00 PM
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This one has me a little perplexed.
We're all familiar with German comparisons of the ability of 20mm and 30mm cannon to destroy 4-engined bombers. It's the source of the widely-quoted 4 30mm shells versus 18-22 20mm shells to shoot down a buff.
Here is one quote from such a document:
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Fuer die einzelnen Kaliber ist folgende Anzahl von Treffern erforderlich, um den Abschuss eines viermotorigen Bombers zu erzielen:
Kaliber 2 cm, Minengeschoss, Sprengladung 18 g, 18 Treffer,
Kaliber 3cm, Minengeschoss, Sprengladung 72 g, 4 Treffer
....
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What I can't figure out is whether the number for 20mm shells refers to total 20mm hits, or to Mine shells only.
Belting for the MG151/20 was 2 Mine shells out of 5, with HE/T (2.3 gms of Nitropenta) making up the remaining 3 out of 5 shells. As Tony has previously told us, the HE/T was retained because unlike the 30mm Mine shell, the 20mm Mine shell wasn't a tracer, and this was considered important.
If that 18 refers to total 20mm shells, then the total amount of HE needed was much less when shooting 20mm than when shooting 30mm, for the same effect.
For 30mm: 4x72 = 288 gm Nitropenta
For 20mm:
18 shells - 2/5 are Mine, 3/5 are HE/T
=(18 * 2/5 * 18.6) + (18 * 3/5 * 2.3)
=159 gm Nitropenta
That's a really surprising result to me. I would have expected it to be much more efficient to detonate a large amount of HE in one place, rather than spread it in many smaller explosions.
However, if 18 refers only to the Mine shells, then in reality it took 45 20mm shells on average to down a 4-engined bomber, as Mine shells were only 2 out of 5.
Now, the total amount of HE becomes:
=(18 * 18.6) + (27 * 2.3)
= roughly 397 gms Nitropenta
This is more in line with my expectations, but it does mean that the oft-quoted 18-22 20mm shells to down a heavy bomber is wrong. It took 45 shells.
Any insight into which interpretation is correct? Is Tony still around?
Thanks,
avin
[This message has been edited by avin (edited 04-08-2001).]
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To me it seems to quite clearly state that 18 2cm Mine rounds containing 18g of explosive is the required amount.
Sprengladung means explosive content
Your quote means "more or less":
For the individual calibers the following number of hits is necessary to obtain the destruction of a four-engined bomber:
2 cm: mine projectile, explosive charge 18 g, 18 hits
3 cm: mine projectile, explosive charge 72 g, 4 hits
18x18g = 324g
4x72g = 288g
I suggest you email gerzz or ireg and ask their opinions.
In my opinion neither of your interpretations is likely to be correct (i.e neither 18 rounds or 45 rounds of a typical mixed belting). The figure of 18 mine shells is very likely a theoretical number not empirical. i.e. they did static tests on captured bombers or bomber components on the ground and created a theoretical requirement of 18 mine round hits. However since a pure mine belting was unlikely this probably meant that something like 300g to 400g of explosives delivered by 20mm rounds would do the trick.
Hooligan
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I can't add anything to the debate about what the Germans meant precisely, but I expect that the belt mix for the 20mm varied according to circumstances. The mine shell was clearly regarded as important and in fact a bigger 20mm version (105g, with 25g HE) was developed.
The Germans later calculated that to down a bomber with a single hit, 500g of HE was required, which led them to develop 55mm calibre guns at the end of the war.
Incidentally, the standard 30mm M-Geschoss did not have tracers. The method of construction made it difficult to achieve this, although they were working on designs at te end of the war.
Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/ (http://www.users.globalnet.co.uk/~autogun/)
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FWIW at the 2000 WarBirds Con, Franz Stigler said that 6 to 8 MK 108 hits to the wing of a B-17 would cause the wing to fail.
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Guys, there are two separate points:
1) As hooli says, these might be theoretical estimates. I'll track down the source - I seem to remember being told they were from gun camera. But what you guys agree with me on is that because of variable loadouts, these estimates can't be used uncritically, as so many LW enthusiasts do. In the field, it would have taken more on average than 18 20mm and more than 4 30mm Mine shells, based on the loadout. Perhaps considerably more.
2) The basic question I'm asking: do we expect the same amount of HE to do more damage when it all explodes in one place, versus broken up into multiple smaller explosions? This is a question at the heart of modelling weapons accurately in flight sims.
I'm guessing that it depends on what you hit, which means that the only way to figure this out is to run a decent simulation.
avin
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An even better question is when will we see the minegeschoss in Aces High?
hispanos got the best of both worlds, LW is stuck with the least effective round.
It's a conspiracy, I tell you (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Baron Claus "StSanta" Von Ribbentroppen
Staffelkapitän 9./JG 54 "Grünherz"
"If you return from a mission with a victory, but without your Rottenflieger, you have lost your battle."
- D. Hrabak, JG 54 "Grünherz"
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Avin:
I recommend that you obtain the following book via interlibray loan.
The Development of German Aircraft Armament to 1945
USAF Historical Studies: No.193
Reading it may shed a little light, and as I recall it is available at a couple of libraries close to you.
Hooligan
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Luftwaffe fanatic wrote:
An even better question is when will we see the minegeschoss in Aces High?
Ummm... about a year and a half ago?
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Vermillion
**MOL**, Men of Leisure
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Yep Verm, unless the results of the Dinger/Hooligan tests have changed, you are right. No other way to explain those results.
Sorry for hijack Avin, I'm moving along now. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
[This message has been edited by funked (edited 04-09-2001).]
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It's a conspiracy, I tell you. StSanta
Another satisfied X file watcher.
At any rate the 151/20 seems to hit awfully girlish. If we got the Minengeschoss shell I bet we have AP loadouts for the FW 190 F8 as well too huh (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
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Sturm6 StaffelKapitän
JV44 Platzschutzstaffel
Airfield Defense Squadron
Campaigning for the rights of the ME-410.
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It required about 20x20mm hits from a MG151 to bring down a heavy buff, have it descired in several books including Adolf Gallands Book.
It's not 20x20 minenshell hits, it's the total of 20x20mm hits.
3-5x30mm hits were usualy required to bring down a buff.
Remember, in AH you actually have to take the wing (or any other very importnatn piece) of a plane to bring it down but in real life it was enough to make it full of holes and that way it would go down and maybe get a crash landing.
In AH you can put 3x30mm in eachi wing of a B17 and a few more in the fuselage, as long as he doesn't actaully loose anything he still flies as good.
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Rasmus "Wilbus" Mattsson
III/JG5 Eismeer
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I bet we have AP loadouts for the FW 190 F8 as well too huh
Didn't Tony post some penetration data on MG151/20 AP ammunition, that showed that it wouldn't penetrate the armor of a Panzer MkIV? So It wouldn't matter either way with the units we have in AH.
And the MG151/20 already kills the M3 and M16 halftrack units quite nicely, and not to mention that we all know the Ostwind is seriously porked.
Its a moot point, the whole armor system for the game is being changed anyways.
Funked, I ordered the TM 9-1985 series last week on WWII German Munitions (both bombs, rockets, and projectile ammunitions). Email me if you would be interested in a copy.
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Vermillion
**MOL**, Men of Leisure
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Verm it might matter considering that the 17 and lanc are armored fortresses (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) At any rate, new armor model will probably mean more squeakin. My Hispano cant kill in 3 hits now will be the first one (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif) Anyway, MG 151 is lacking and we all know it, its a fact and we should be up to par soon i hope.
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Sturm6 StaffelKapitän
JV44 Platzschutzstaffel
Airfield Defense Squadron
Campaigning for the rights of the ME-410.
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Originally posted by Vermillion:
Didn't Tony post some penetration data on MG151/20 AP ammunition, that showed that it wouldn't penetrate the armor of a Panzer MkIV?
Actually, the data he posted showed that it should penetrate the armor in certain areas.
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In tests I did with my roommate, he removed my Lancaster's wing with 12 rounds from his P-38L's 50cals. 3 rounds from each gun, no 20mm. Those 12 rounds removed the inner section of my Lanc's right wing.
The problem it sounds like you guys have is that you aren't accurate enough. The total amount of punishment that a Lanc or B-17 can take is impressive, but its individule sections can't take much. If you focus on the outer or inner section of either wing (don't switch between wings) it will quickly pop off, dooming the bomber. If you spread your fire over the entire bomber though, it will absorb a tremendous beating and remain in the air, under control.
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We few, we happy few, we band of brothers;
For he to-day that sheds his blood with me
Shall be my brother
Bring the Spitfire F.MkXIVc to Aces High!!!
Sisu
-Karnak
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Wilbus,
I have no reason to believe Galland's statement was independently derived, and can't imagine how he would have derived it. Apart from potential one hit killers like the 30mm and 37mm, the only estimate for hits/kill I've seen is Sakai's P39 shootdown with 4 20mm shells - and the circumstances around this one were very unusual (he saw 4 puffs, and only 4 shells were fired).
I personally can't derive such an estimate from the main arena in a flight sim without the "score" hit percentage. It would be impressive to see a study done by an ace in the real deal.
I would imagine Galland was quoting the results of LW tests such as the one I quoted. These tests don't translate into real life hits/kill in a straightforward way, as I once thought.
Unless you know otherwise?
avin
[This message has been edited by avin (edited 04-10-2001).]
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going little OT, but after luftwaffe staff began to record and research fighter statistics they found out incredible things from Hans-Joachim Marseille "Star of Africa";
Guenther Rall:"We found that Marseille needed an average on of only fifteen (15) bullets per kill" !!!
On one sortie he scored 6 kills and used less than half of his 109 ammo !
Of course Marseille was exceptional pilot and so this should not be generalized, but just think... 6 kills in 109 and more than half ammo left ! Not any rubber bullets, tho.
He flew 109E-4 ? and/or 109F-4 ? anyone ?
[edit]From "Horrido ! Fighter aces of the Luftwaffe": The wartime combat reports of the Luftwaffe fighter pilot were highly detailed. Every evening you had this business to go through. Witness, air witness, ground witness, your account of the combat, the type of enemy aircraft, the kind of ammunition you fired, the armament of your aircraft, and how many rounds of ammunition. These reports were nuisance to us, but when I was on the staff of Galland I saw how valuable they could sometimes be" by Guenther Rall.
So all were recorded really accurately.
[This message has been edited by janneh (edited 04-10-2001).]
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Hi avin,
2cm M-Geschosspatrone 151
Patronengewicht: 183g
Geschossgewicht: 92g
Geschossfüllung: 18,6gr Nitropenta.
< Edited >
The Documets are right but you have to understand it. They say, to get down a bomber, you need 18 20mm or 4x30mm shells.
This based on calculation, how many Explosivfilling you get on the target.
You have to read all documents. Hm, how i can tell you. lets see .
Here is a small Table from a Mauser research Document.
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Weapon : 500m to target: 1000m to target
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MG151/20 : 11 x 18 = 198 : 22 x 18 = 594
MK108 : 12 x 4 = 48 : 30 x 4 = 120
MK103 : 10 x 4 = 40 : 26 x 4 = 104
----------------------------------------
Now the story.
The MG151 has to fire 198 shells to get 18 statistical hits on a 500m target.
The MK108 has to fire 48 shells to get 4 statistical hits on a 500m target.
All based on 10% hitratio and and reviewed
with groundtest on bomber and Guncams.
I can show you much more Charts original from mauser.
< edited >
Karl
[This message has been edited by Karl (edited 04-13-2001).]
[This message has been edited by Karl (edited 04-13-2001).]
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Karl,
Ignore the part of Avin's post that says: it does mean that the oft-quoted 18-22 20mm shells to down a heavy bomber is wrong. It took 45 shells.
And lets move the discussion closer to what we see as an interesting issue. I think we can generally accept the number of M-geschoss as shown in the tests, but, the main question becomes: how do we get 18 hits of 20mm M-geschoss in a operational situation if not all the rounds on the belt are M-geschoss?
We'd have to score more hits of all the types in the belt before we approach 18 hits of purely M-geschoss. If we have non-M-geschoss in the belting, how does this affect the average numbers of rounds it takes to effect a shoot-down? I would suspect it goes up some since those rounds contains less explosive. But how much higher can we suspect that average to become (maybe this gets into the realm of putting angels on the head of a pin)? The other rounds are usually HE/I correct? Does the incendiary effect "hold its own" when it comes to starting fires that leads to the shoot down?
Were other tests done using all the rounds present on an operational belting as opposed to a purely M-geschoss loadout? Where does the number 22 come from (it seems quoted so often) as opposed to this document specifying 18? Do we know where these other tests came from?
buile-
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Gerzzz,
I've tracked down the original document I quoted from. My German is very poor, but that 18 Mine shells indeed appears to be a theoretical estimate, as hooligan (and buile) explained already.
Gerzzz wrote:
The MG151 has to fire 198 shells to get 18 statistical hits on a 500m target.
The MK108 has to fire 48 shells to get 4 statistical hits on a 500m target.
All based on 5-7% hitratio and and reviewed
I think you'll find that 18 hits out of 198, and 4 hits out of 48, is not a 5-7% hit ratio.
avin
[This message has been edited by avin (edited 04-13-2001).]
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Gerzzz:
Is that really you? I would have never guessed it from the tone (http://bbs.hitechcreations.com/smf/Smileys/default/frown.gif).
I am terribly interested in finding out exactly what light the Mauser documents can shed on this particular question. I don't know where Avin's document comes from but it does seem to quite clearly state that 18 Minengeschoss (not just 20mm but specifically M-shells) are required. Do the Mauser documents make any similarly specific statements about number and type of rounds?
Hooligan
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I have seen a Luftwaffe figure of only 2% of rounds fired actually hitting the target.
As a matter of interest, I have also read that the Polish air force reckons 6% hits for their MiG-29s, and a Tornado F3 pilot tells me that a really good shot can land 20% of shots fired on a towed drogue target (nice and steady, with a radar reflector to help the radar gunsight.....)
Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/ (http://www.users.globalnet.co.uk/~autogun/)
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edited
[This message has been edited by Karl (edited 04-13-2001).]
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appears to be a theoretical estimate. hooligan (and buile) explained this to me already
Theoretical in so far as conducting tests presumably against static targets like Hoolign said. However, the results are further bolstered by examination of gun camera apparently from operational use.
They are using a nearly 10% hit rate as determined from guncamera of the "better" pilots.
buile-
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[edit] No need to keep this up.
[This message has been edited by avin (edited 04-12-2001).]
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I suggest we put the issue of tone in this thread behind us. Lets start with a clean slate, please, and ignore the tone issue unless:
a: we decide to join a private discussion.
b: tone becomes a problem in the private discussion.
I am interested in the discussion here, and would rather not have this issue become a barrier to examining it.
buile-
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I'm interested in any discussions on these types of issues, but I'm way too busy to start checking yet another BBS or mailing list each day.
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Vermillion
**MOL**, Men of Leisure
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Hi,
i have translating some parts. Sorry about my lack of english. But i hope you understand it.
--------------------------------------------
Forderung an die Entwickung von FLiegerbordwaffen.
Bühler, Berlin,
1) based on the expierience we have in the last month of war,
we need only 2 kinds of Ammo for destroying flying targets.
1.1) Geschosse mit Brandwirkung
( Projectiles with fire effect)
1.2) Geschosse mit Minenwirkung oder Gasschlagwirkung
(Projectiles with mine effect or muzzle blast effect)
Projectiles with major penetration values are not needed, while
the airia of armored surfaces of the plane is very small. So we dont
need further development for Ammo with higher V0 to penetrade Amor.
We need only the V0 to get the Ammo to the target and the correct calculated
Ignitiontime with delay.
...
Projectiles with fire effect is very usefull against the B17. The B17 has hughe
Fuel tanks in the wings. On the other side the B24 has there fuel tank placed in
the Fuselage and only small tanks in the wing. Here works the "Brandmunition" with
less effect.
Projectiles with Mine effect / muzzle blast effect works on both planes good.
...
2) possebility of the probability of hit ( Thats right ? oha )
The probability of hits is based on:
2.1) Projectile flying time ( V0 )
2.2) Form value of the projectile
2.3) Rate of fire
2.4) Weapon dispersion
2.5) Stability of the airplane ( effect the Hitrate of the pilot )
2.6) % Hitrate of the pilot ( german word "Abkommengenauigkeit" )
If we do a calculation about a special muntion , how much Rounds we need
to get hits, we will determine, that there is only a small different between
high und low V0. The pilot need with the 3cm MK108 ( V0 = 505m/s ) at 500m Combatrange
22 Rounds per hit and with the 3cm Mk108 ( V0 = 870m/s !! ) at the same range 19 rounds
per hit. The same calculation at a target distance 1000m the values are 57 and 51
rounds per hit. We calculated this based on a 10% Abkommengenauigkeit >8)
( Pilot hitrate ) reviewed from many "Frontfilmauswertung" ( Guncam ).
Eine 95 prozentige Trefferwahrscheinlichkeit bei Gaußcher Kreisverteilung der Schüsse ist dabei errechnet. " Hm hard to translating" ( 95% probability of hit during Gauss set distribution of the shots is thereby calculated.
Numbers of needed Hits to get a 4 MOT Bomber down:
--------------------------------------------------
2cm Minengeschoss, Sprengladung 18g, 18 Treffer
3cm Minengeschoss, Sprengladung 72g, 4 Treffer
5cm Minengeschoss, Sprengladung 350g, 1 Treffer
5,5cm Minengeschoss, Sprengladung 420g, 1 Treffer
--------------------------------------------------
These values are as averaging value from GunCams and Tests determined.
-------------------------------- end.
The Document is much longer with much data.
Anyway, my resume of this is:
Yes, 4 30mm hits to get down a Bomber IS possible. BUT, you have to hit at the right places. Not always 4 hits causing a destroyed Bomber. The numbers are average.
Karl
[This message has been edited by Karl (edited 04-13-2001).]
[This message has been edited by Karl (edited 04-13-2001).]
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Need more data ?
Karl
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The question now becomes (in relation to the 20mm): if the pilots are not firing all M-geschoss from their guns, how does this change the average number of hits to effect a shoot-down? Since there is less HE in the non-Mine rounds, we'd expect the number to rise. How high can we expect the number to rise?
Should we begin looking at the issue in relation to the gram weight of explosive needed like the way Avin was pondering? Or, does the different effects of the ammunition (incendiary vs pressure effect) throw that off (not linearly related)? By how much can we expect?
That's why we're wondering about the primary source for the oft-quoted "22 average hits" to see how that number was arrived at. Or, what about any pilots who studied the number of hits they took (with an operational belting).
Yes, 4 30mm hits to get down a Bomber IS possible. BUT, you have to hit at the right places. Not always 4 hits causing a destroyed Bomber. The numbers are average.
Yes, the number is an average, but i wouldnt get *overly* strict on the placement of those rounds. You dont the all 18 hits to be in the right place, you need, on average, 18 hits to get the subset needed into the right places. That's what i think. Otherwise, you'd say you need an average of 3 20mm hits to down a bomber (but all 3 hits must be to the cockpit). It's: how many hits do you need on average to get enough in the right places for a shoot down? 18 M-geschoss. Okay, now how many with a normal belting? (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
buile-
[This message has been edited by buile (edited 04-13-2001).]
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Hi buile,
maybe i can help you.
avin wrote:
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Belting for the MG151/20 was 2 Mine shells out of 5, with HE/T (2.3 gms of Nitropenta) making up the remaining 3 out of 5 shells. As Tony has previously told us, the HE/T was retained because unlike the
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Avin, where did you get these belting numbers ? Please sources ?
The problem is, there are much different belting setting for special targets.
I am sure, that "Reichverteidigungsgruppen" like JG300 used different belting like JG at east or west front.
Lets see,
Belting: Stand 03.44
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2cm
a) Jäger westfront:
1 M-Geschoß-Patr.
1 Brandgr. Patr.
1 Panzerbrandgr. Patr.
b) Jäger eastfront:
3 M-Geschoß Patr.
1 Brandgr. Patr.
1 Panzerbrandgr. Patr.
c) Kampf u. Schlachtflieger
3 M-Geschoß Patr.
1 Brandgr. Patr.
1 Panzerbrandgr. Patr.
I found no sources about the belting for the
"Reichverteidigung" Geschwader like JG300 .
I am sure, they use against 4 Mot Bomber different Belting than Jäger.
Karl
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"The same calculation at a target distance 1000m the values are 57 and 51
rounds per hit."
Is this saying that at 1000m you get about 1 hit for roughly 50-60 rounds fired?
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first i have to thank you buile for
lighning me up for avins problem .
- - -
here we go.
Avin,
the Documents show 18 Hits 20mm ( 18.2 nitropenta) to shoot down a bomber.
Thats a average number and we can used this as ok. But now i understand you problem and maybe the misunderstood from other people.
you wrote:
-----------
However, if 18 refers only to the Mine shells, then in reality it took 45 20mm shells on average to
-----------
Yes you are right, this numbers can change on
different belting setting ( see uper post).
Even the number 45 is statisticle, while it can changed on different target range.
remember:
MG151/20 : 11 x 18 = 198 at 500m targetrange.
This numbers are statisticle if you shoot
M-Schell rounds only. If you based the belting mix, you have to shoot much more than 198 shells to get 18 M-Schells hits.
Karl
[This message has been edited by Karl (edited 04-13-2001).]
[This message has been edited by Karl (edited 04-13-2001).]
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Hi toad,
you wrote:
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Is this saying that at 1000m you get about 1 hit for roughly 50-60 rounds fired?
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i can give you a " YES " you are right. 1 hit / 50 - 60 rounds.
Thats why the Luftwaffe got the command to get close to fire. Planes with 30mm Cannons have to open fire less ! 300m or closer !.
Karl
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Avin, where did you get these belting numbers ? Please sources ?
I think i told Avin a basic loadout of 2 Mine rounds per 5 in the belt-- regardless, you can find a basic belting from emmanuel gustin's site. Yes, the belting can change, but i think it's good to be conservative.
If you based the belting mix, you have to shoot much more than 198 shells to get 18 M-Schells hits.
My personal view is that it's not 18 hits of Mine rounds in total combined with every other type possibly fired. Using a ratio of 2 M-geschoss per 5 round fired (we'll say the rest are HE/I), i think you'll start getting things like 10 Mine rounds + 15 HE/I (25 avg) or 12 Mine rounds + 18 HE/I (for 30 round avg)... more? Yes possibly, but IMO, not 18 Mine + 27 HE/I as an average.
This numbers are statisticle if you shoot M-Schell rounds only.
Yes, that's exactly what Avin is asking about. And since we shouldnt be shooting all M-geschoss, then we cant use that number as a *cut-and-dry* benchmark for flight sim damage models.
buile-
[This message has been edited by buile (edited 04-13-2001).]
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From:
"The Development of German Aircraft Armament to 1945", USAF Historical Studies #193, Oberst Ing
Page 32
(Luftwaffe) Tests had disclosed that it was not the grenade splinters but the blow-back effect of the thin-walled mine projectiles which brought about large-scale damage combined with incendiary effect in the aircraft hit. The effectiveness of 20mm, as compared with 30mm mines, was approximately 1:4, and in 1944 four or five hits by 30mm projectiles, concentrated in a relatively small area, were necessary to bring down a four-engine bomber.
…..
The initial experiments revealed that 420g-450g of explosives were needed in order to bring about the desired total damage to the fuselage or wings of a large bomber.”
This 420g-450g explosive content requirement led to the development of the German 55mm aircraft cannon. For reference, a mk 108 30mm round contains 72g of explosive/incendiary mixture
From this source and what Karl has said I think it is likely that the requirement is for 18 2cm Mine shell hits within a relatively small area. I would like to hear if Karl has anything further to add on whether or not it was a requirement for the 18 Mine round hits to be fairly concentrated.
The Germans increased the ratio of Mine shells when the expected target was a 4-engined bomber. Since apparently a consideration for including HEI/T was their tracer properties and since we are speculating anyway: It would make sense for a bomber mission to belt something like 4 Mine, 1 HEI/T. 20-25 hits from this belting would yield something close to 18 Mine hits with a few added HEI/T hits.
Since the standard belting in the West was:
2cm
a) Jäger westfront:
1 M-Geschoß-Patr.
1 Brandgr. Patr.
1 Panzerbrandgr. Patr.
That is:
1 Mine
1 Incendiary
1 AP/I
One can only assume this is an anti-fighter belting, as opposed to a Mine-rich anti-bomber belting. This leads to 2 conclusions: 1) That against Western fighters, incendiary and Armor Piercing rounds were more desirable than Mine rounds. 2) That a Mine-rich belting optimized for 4-engined bombers would not work as well as the standard belting against enemy fighters. I would also be particularly interested in Karl and Tony Williams think of these conclusions.
Hooligan
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Apologies for jumping in.
This leads to 2 conclusions
I cant say if Mine rounds were less effective vs fighters or not. To quote Karl's translation:
1) based on the expierience we have in the last month of war, we need only 2 kinds of Ammo for destroying flying targets.
It suggests that a Mine/Incendiary mix would do the job if they include fighters as a "flying target." I would think that the pressure effect would remain effective against a fighter and its smaller airframe.
I'd like to verify this next part, but i seem to remember the Mine rounds were favored against the heavily armored IL-2. Where the AP ammunition had a tough time versus its armor, the Mine rounds were extremely effective at tearing away the rest of the plane around that armor. Therefore in the end, it was more effective than AP.
I have also heard that there was a supply issue with Mine rounds. Can anyone confirm this and/or its extent? That could provide another reason to suggest not using a lot of Mine shells in an anti-fighter role when there's abundant AP or Incendiary to use up. Ie, youre in a situation where you have possible shortage of a round that works well vs bombers and fighters, and you have an abundance of rounds that work well vs fighters, but not quite as well vs bombers. The suggestion to save the Mine round for the bombers seems obvious if that's true.
That against Western fighters...
What could be possible differences between the two fronts that will give different results? I wouldnt think it's strength of armor because of the IL-2. Anyone have other ideas?
I would like to hear if Karl has anything further to add on whether or not it was a requirement for the 18 Mine round hits to be fairly concentrated.
As i mentioned before, i'm afraid of people becoming *overly* strict in their interpretation of what "fairly concentrated" or "relatively small area" means. I can see people envisioning this as a 6 foot by 6 foot area, and i simply dont think that was the case. I think we've all seen the results of RAF tests of 20mm ammunition on static examples of wings with fuel tanks (thanks to whoever provided those for us); the rounds were effective in setting them alight under the test conditions. It wont take 18 Mine shell hits to a fuel tank to set it on fire.
So, imo, where you are on the bell curve depends on where your strikes mostly occur: if you're hitting a less-vulnerable area like the fuselage (which has less chance of fire), i'd think you'd need a larger amount of hits for good concentration to achieve massive structural failure. If youre hitting vulnerable areas like the wings, you dont need to use the explosive to brute-force a massive structural failure; you just need enough hits to ensure the fuel tanks or engines are damaged to the point of fire.
This is a heartless subject isnt it? (http://bbs.hitechcreations.com/smf/Smileys/default/frown.gif)
buile-
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I wouldn't get too hung up on exact numbers of hits required. They would only have been approximate averages and in practice bombers were doubtless brought down by only one hit, and conversely survived dozens.
I suspect that M-Geschoss were considered more important against bombers than fighters because of the density issue. There wasn't much empty space in fighters, except in the rear section. Hits scored were statistically more likely to hit armour or engines, so some AP capability was useful. Bombers, on the other hand, were full of empty space through which AP would pass without doing significant damage. This is where the ability of the M-Geschoss to strip away aircraft skin by blast effect came in.
Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/ (http://www.users.globalnet.co.uk/~autogun/)
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Buile wrote:
but i seem to remember the Mine rounds were favored against the heavily armored IL-2...
I believe you are wrong on this. Here is a quote from Gustin's ammuntion page concerning the belting of the 20mm Mg151.
20 mm (MG-FF, MG 151/20)
2 Minengeschoß m. Zerl.
2 Brandsprenggranatpatronen L'spur m. Zerl
oder Brandgranatpatronen
1 Panzersprenggranatpatrone o. Zerl
oder Panzerbrandgranatpatrone (Phospor) o. Zerl.
Here the Minengeschoß appears for the first time. A version of the 20mm M-Geschoß with tracer did not exist, so tracer was used on HE/I (Brandsprenggranatpatrone) or pure incendiary (Brandgranatpatrone) rounds. The latter was apparently a new development in 1944, intended to replace the less effective HE/I. The fifth round was a semi-AP projectile, explosive or incendiary. Apparently the main reason this was used instead of a solid AP round was that a solid projectile would have been too heavy.
It was recommended that more AP or semi-AP ammunition would be loaded when the probable targets were well-armoured attack aircraft such as the Il-2. On the other hand, against the four-engined bombers of the RAF and USAAF the high explosive types were more effective.
The Mine round was apparently not that effective against IL-2 and the Germans used an AP-rich mix when IL-2s were the intended targets.
I also consider it improbable that a shortage of Mine rounds was the reason for the belting against Western fighters. Consider the belting used on the East front. Karl wrote:
b) Jäger eastfront:
3 M-Geschoß Patr.
1 Brandgr. Patr.
1 Panzerbrandgr. Patr.
Or
3 Mine
1 Incendiary
1 AP/I
Why would they be using a Mine-rich belting on the East front if Mine rounds were in short supply? Does it make sense to sacrifice a Mine-rich belting as the standard on the Western front where you would expect to frequently run into 4-engined bombers so that you could use a Mine-rich belting on the Eastern front? I think not. I don’t that supply problems with Mine rounds was the driving force behind the belting arrangements.
I believe that Mine rounds were simply less effective against Western fighters because of their very poor armor piercing capabilities (much worse for example than Hispano HE/I rounds). After all, US fighters were the largest, most durable and best-armored fighters of the war (excepting the especially modified German bomber interceptors). The value of AP-type rounds against these exceptionally well-protected US fighters seems obvious to me. By Western standards, Soviet fighters were rather small and lightly armored, thus the higher proportion of Mine rounds recommended for the Eastern front belting.
Hooligan
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US fighters are heavily armored. LoL are you nuts?
Exactly which areas of P51 are heavily armored? Where is the surface skin of the P38 armored. Granted the P47 is tough but where is its entire surface armored? Did it have 10mm thick steel skin everywhere? They were well built but not armored, for gods sake please guys stop the constant feel good flag waving.....
Armor plated P51s I love it, damn thats funny. As for mine shell penetration all it has to penetrate is the outer skin of a plane, which is usually thin aluminum then it blows apart the structure with massive overpressure caused by the explosion. So unless a plane has heavy external surface armour it presents mineshells no problem. Il2 actually had 8-10mm thick STEEL plates as an integral skin surface in many areas, this is why a higher AP load was called for and why HE rounds were less effective.
Which one of you here belives US fighters has 10mm thick STEEL outer skin, show of hands please......
If As you say Mineshells were good vs heavy bombers why wouldn't they be vs small fighters, maybe im off base but I think some of u guys are afraid if a mineshell comes to AH. O yes and as for your guys supposed mineshell "test", I dont think its valid. Hangars and planes dont have the same damage model. So when you do a real and valid test tell me bout it, till then im convinced that mishell isnt presently in AH MG151/20.
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HI,
only 1 remark:
1) If Target = 4 Mot Bomber then different Belting Mix than a) .. Westen.
I have not the exact numbers. But they used much more M-Schells.
[This message has been edited by Karl (edited 04-14-2001).]
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Grunherz, why don't YOU do that test ? If you don't believe what work has been done in the past is correct, step forward and prove your point.
You always seem so quick to complain, criticize, and down right squeak and moan, but I never see you step forward to do any of the actual work.
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Vermillion
**MOL**, Men of Leisure
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Thanks, Karl.
I just thought that was a pretty interesting fact, given all the players here that have assured everyone that any hit at 1000 meters is simply impossible.
Interesting thread.
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CC Verm what kind of test procedures would you reccomend, what kind of errors should I watch for, seriously?
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Grun:
As you know, no fighters had armored skin or anything like the armor coverage that a sturmovik had.
However US fighters typically weighed 25% more than their European counterparts and had better armor coverage for the pilot, parts of the engine etc... The reputation of extreme toughness that P-47s, Corsairs and Hellcats had was well deserved.
There is no doubt that Mine shells were effective against US fighters but the evidence suggests that other types of rounds (AP/I, Incendiary) were more effective than Mine rounds.
Or do you believe that the Germans were idiots for selecting the belting they did to use against Allied fighters?
Hooligan
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I wouldn't get too hung up on exact numbers of hits required. They would only have been approximate averages
Yes, that's why i think of it in terms of a bell curve.
but i seem to remember the Mine rounds were favored against the heavily armored IL-2...
------------------------------------------------------
I believe you are wrong on this.
Ok, i will accept that. If i follow the source of the reference made on this, i find that it refers to the 30mm Mine shell and not the 20mm Mine shell vs IL-2s. It would seem that the 30mm Mine shell was superior against heavily armored targets than 20mm AP or semi-AP.
...the Germans used an AP-rich mix when IL-2s were the intended targets.
In general, i'm not trying to make an argument here, but i honestly wonder the feasibility of this? How often can you predict what your target is going to be in order to choose different extremes of belting options... meaning heavy on the AP or heavy on the HE?
US fighters were the largest, most durable and best-armored fighters of the war.... The value of AP-type rounds against these exceptionally well-protected US fighters seems obvious to me.... The reputation of extreme toughness that P-47s, Corsairs and Hellcats had was well deserved.
Yes, the P-47's toughness was certainly recognized by the GAF. Corsair and Hellcat didnt make much appearance in the ETO, so i'll leave those out. P-47, yes, very tough. The GAF didnt consider the P-51 anywhere near the same level of durability of the P-47. In fact, i would say their overall impression of the Mustang was one of vulnerability to cannon fire, so i'm not sure how much they felt forced into a certain belting option, at least vs the P-51.
There is no doubt that Mine shells were effective against US fighters but the evidence suggests that other types of rounds (AP/I, Incendiary) were more effective than Mine rounds.
That is very possibly true. But, is it unreasonable to suggest that an overpressure force is higher when you try to constrain it in a smaller area, than in a larger area?
buile-
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Aircraft can be destroyed because accumulated structural damage causes structural failure (the wing comes off) or a single hit on a critical component (like the Pilot's head) can finish the aircraft.
Bombers don’t die as readily from a critical hit as fighters do. Losing one engine or pilot in a bomber is not a guaranteed kill as it is in a single-engined fighter. One hit in any number of “right places” on a fighter is going to take it down, as long as that hit penetrates sufficiently. I believe this is why the Germans did not favor a Mine-rich belting against Western fighters. Conversely, bombers are much more difficult to kill with a single critical hit, making structural failure a more reliable killing mechanism. This is why the German’s did favor a Mine-rich belting against bombers and why the US favored cannons for bomber interception, while largely sticking with .50s for anti-fighter roles.
Hooligan
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hooli wrote:
That is:
1 Mine
1 Incendiary
1 AP/I
One can only assume this is an anti-fighter belting, as opposed to a Mine-rich anti-bomber belting. This leads to 2 conclusions: 1) That against Western fighters, incendiary and Armor Piercing rounds were more desirable than Mine rounds.
Curious wording, hooli. I'd have phrased that as: against fighters, incendiary and AP rounds were *as* desirable as Mine rounds. Or did you forget that the Germans did retain some Mine shells, suggesting it wasn't as undesirable as you think. Shouldn't they have dropped it entirely if that was the case?
We know the ballistics of the Mine round were poorer than other rounds. It's possible the tradeoff with a high Mine belting was worthwhile against bombers, and less so against fighters. Fighters are tougher to hit than bombers in formation. But if a Mine round did hit a fighter, it might often do considerably more damage than any other type of shell. No way to know for sure without more evidence, either theoretical or historical.
But we've had this conversation before.
Karl, I did get an answer to my original question. Thanks.
avin
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Avin:
Here is my reasoning.
1) Mine round ballistics are better out to 250-300 yards because of their higher initial velocity. I don't think that ballistics beyond 300 yards would carry much weight for belting considerations (at least against fighters).
2) If Mine rounds were equally as good against fighters as the other types, then why not just go with a Mine-heavy belting in the West? After all, you might run into bombers. Why bother with a separate belting for bombers and fighters if the bomber-belting is just as good against fighters as the fighter-belting. It only makes sense to have a separate fighter-belting if that belting offers some significant advantage. That is why I am currently of the opinion that Incendiary and AP/I rounds are "more" desirable rather than "as" desireable.
Obviously no single round was considered desireable to the exclusion of all others. The German's didn't choose to have any pure-mine or pure-anything beltings. No doubt they were hedging their bets since they did not have perfect information on exactly how well all of the rounds worked and exactly what targets would be engaged on any particular mission.
Hooligan
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Obviously no single round was considered desireable to the exclusion of all others.
Though when the 30mm came out, they apparently found the Mine round (or Mine, HE/I combination) satisfactory enough to do away with AP.
If Mine rounds were equally as good against fighters as the other types, then why not just go with a Mine-heavy belting in the West?
We have to give some kind of credence to the belting suggestions. So *why* wouldnt they give the same kind of belting suggestions in the West as in the East? It does suggest, as Hooligan argues, that there was benefit for it. But like Avin mentions, with a 1:1:1 ratio, it does suggest that the Mine round was equally important as the other rounds.
No doubt they were hedging their bets
But why weren't they hedging their bets on the eastern front? The IL-2 figured as a prominent target in the east.
I do not know the thicknesses of armor used on most Russian aircraft, but one interesting point is that the Mine round really has no armor penetration ability, suggesting even light armor could stop it. So i think the argument might have to look at general construction. Yes, allied planes were heavier, but also simply bigger, and the Mustang didnt have a reputation in the GAF as a durable machine regardless of that size and weight (but still more durable than most Russian fighters? I dont know). Ah, yes, i forgot about placement and quantity rather than simple thickness....
But i will say that Hooligan's POV is one that wont miss the forest for the trees. And until, as Avin says, we find something new, then in general it's a basic and logical stance to take, regardless of lots of niggly issues that show it might not be so cut and dry. In this kind of forum, there's always a defense mechanism because the results of these arguments can become an exagerrated model in a very competitive game. Sometimes we dont know the extent of what people are arguing: there's a difference between a round being "ineffective" and being "not as effective." I hope that point is clear.
While it may play no role in this discussion, it would still be nice to know about the supply situation in regards to the 20mm Mine round. There are different reasons why you order people to use up the existing stocks of normal HE and AP 20mm ammunition, and only one of them, i suppose, is that the demand for the round was outpacing production.
It isnt too far fetched when we see that a parallel in the Luftwaffe exists with the production of the SD 1 bomb. It was the best munition available for interdiction and anti-personell missions, but there simply wasnt enough of them produced to use on a large scale (entire prodcution of 335,000 could have been used up in one day). While production is apparently not the *only* reason that kept the bomb from being used on a large scale, it does show that it can happen.
I only bring it up because it is just *one more* piece of the historical picture.
I kind of have a question for Tony, but i'll post it after i check something first, or if he doesnt mind, i may email it directly?
buile-
[This message has been edited by buile (edited 04-16-2001).]
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hooli wrote:
If Mine rounds were equally as good against fighters as the other types, then why not just go with a Mine-heavy belting in the West?
I don't know, hooli. It's an interesting question. I can think of literally half a dozen possible answers, and I'm sure if I put my mind to it I could think of more than that. Possibly the most trivial is that some in the LW still hadn't realized that the Mine shell would do the job better than AP even against fighters. Who knows?
Your own suggestion is one interesting possiblity. But that's all I see it as, and I still find it curious that you leap to it without considering other alternatives.
For one, I don't know that the LW in early 1944 was even designating missions for anti-fighter sorties. I seem to remember they were no longer allowed to do anything at this time but concentrate on bombers.
And I simply don't buy the idea that Western fighters were considerably more durable than VVS jobs in 1944. yaks were fragile, but lavochkins had a solid reputation as survivable aircraft. I seem to remember that IL2s made 25% of the sorties flown on the Eastern Front, while 4-engined bombers made less than 5% of the sorties flown. I think I've seen the same source as buile - that the solution to the Il2 was considered to be the 30mm Mine shell, though AP was also tried. I have descriptions of 109Gs shooting control surfaces off the armoured shell with 20mm HE, after which the plane augered. So 20mm Mine did work, but I can't know how effective they were.
As I said already, I'd need more information than we currently have to know what we can conclude from LW belting. I'll keep my eyes open.
avin
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One thing I have learned is that whatever the textbooks might say, what was actually loaded into the ammo belts might be quite different, depending on individual pilots' preferences or simply on what was available.
The most amazing fact about Lw ammo loading I have come across recently is that some MK 108 cartridges were loaded with Hartkernmunition. Now think about that for a moment. The MK 108 was designed around M-Geschoss and Hartkern has never been mentioned as an option in any documents I've seen; the Hartkern was designed for anti-tank use from the MK 101 and MK 103 high-velocity cannon and was pretty useless in any other context.
When I first heard this I thought it was a con. Then I saw for myself dozens of these rounds, recently recovered from a German lake where they were dumped at the end of the war.
There is no logical reason I can think of why Hartkern might be loaded into a MK 108, except that the stuff was lying around in the factory and they didn't have anything else to load. So maybe there was a 30mm M-Geschoss shortage at the end of the war. Who knows?
Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website: http://www.users.globalnet.co.uk/~autogun/ (http://www.users.globalnet.co.uk/~autogun/)
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Tony, sounds to me that you might be on to something. Does anyone actually know how much the germans produced M-geschoss ammo and were they able to satisfy the demand? Or was there M-geschoss ammo lying around unused too?
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SageFIN
"I think I´ll believe in Gosh instead of God. If you don´t
believe in Gosh too, you´ll be darned to heck."
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Nice pic (http://www.kolumbus.fi/staga/mk108blenheim.jpg)
Makes me wonder if LW's 30mm should have more power...
[This message has been edited by Staga (edited 04-19-2001).]
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And I simply don't buy the idea that Western fighters were considerably more durable than VVS jobs in 1944. yaks were fragile, but lavochkins had a solid reputation as survivable aircraft. I seem to remember that IL2s made 25% of the sorties flown on the Eastern Front, while 4-engined bombers made less than 5% of the sorties flown. I think I've seen the same source as buile - that the solution to the Il2 was considered to be the 30mm Mine shell, though AP was also tried. I have descriptions of 109Gs shooting control surfaces off the armoured shell with 20mm HE, after which the plane augered. So 20mm Mine did work, but I can't know how effective they were.
Hmmm..ive heard that mgeschoss ammo didnt work very well against many russian planes due to woodwork structures. Explosion couldnt cause such critical overpressure inside the fuselage as it could to aluminum skinned aircraft. This was because wood was blown off in small chunks letting energy of explosion to escape more easily. That is from few russian sources.
One russian WB pilot once sent me picture of Yak-1(?) with 1x30mm mgeschoss hit in its tail. Ive lost that pic, but it showed many holes (from almost football to pea size)rear from yaks cockpit. It looked very convincing(sp?) IMHO. Im not any specialist though.
About how much 20mm MG151/20 and 30mm MK103/108 rounds were needed to down viermots. I have german test charts which gerzzz once posted at AGW board.
Among other things (loads of weapon/ammunition and range data)it lists:
netw. Treffensahl (rounds) firing time with 5% accuracy [sec]
mg151/15 (75) [22,8]
mg151/20 (20) [9,32]
mg213/20 (20) [5,0]
mk103 (5) [7,4]
mk108 (5) [5,0]
mg213/30 (5) [2,0]
mk50 (1) [24]
note that each 20mm is considered to carry 18.7g, each 30mm 72g, 50mm 350g of explosives. Most likely PETN.
If you need that chart plz send me email and ill mail it to you.
[This message has been edited by illo (edited 04-19-2001).]
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As a sidenote, If i remember right it was ossi's (WB german FH) granpa Georg Amann(LW ace who flew 262, 190 and 109) who said pilots could choose their ammo belting due to their own preferences. Different beltings were used for different missions.
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Thanks for the posts, illo.
Is there any chance that we can ask ossi's grandfather which belting he in fact preferred, and why?
Did he even match his belting to his mission, or did he prefer one sort of belting that was effective in different situations?
I can't wait for a sim that models variable loadouts, as well as provides a decent damage model that allows comparisons of their effectiveness (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif).
avin
[This message has been edited by avin (edited 04-23-2001).]
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Ossi flew in german Warbirds freehost in JG26. I havent played WB for some time. I think we(?) will see him at WW2ol open beta.