Author Topic: SHvak cannon  (Read 2814 times)

Sorrow[S=A]

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SHvak cannon
« Reply #15 on: August 26, 2000, 12:19:00 AM »
Carl-
We have actually very low dispersion now compared to beta days. And yes the ShVAK had a very long barrel. The effect you see is mostly an optical one caused by the poor gunsight in VVS planes. A measurement by Leonid of both guns firing pattern in the dirt showed them equal in dispersion with La-5 slightly tighter. (which makes sense with guns in the nose)

Buffalo- FaF rarely saw ShVAK firing 20mm shells until continuation war. These shells did their job very well thank you, almost all were explosive but both mauser and ShVAK had the same problem with non-detonations if they didn't hit something solid. AFAIK there was no AP ShVAK common- it's just that HE ones often failed to detonate. This was often the case in 109's, I remember at least one example were a 109 had several 20mm rounds lodged in his radio that failed to detonate- it still knocked the plane from the sky however. One doesn't fly away with too many 2 cm holes through you plane.

As for the lead point- it is moot. G2 and La-5FN have almost identical turn rates. Yonder finnish aces that got away with climbing spiral turns were lucky they weren't against experienced LA pilots. An LA-5Fn could have easily sniped such a foolish manuever out of the air if the fight was low enough. However ..  history is written by the ones who get away with such things- not by the ones who die trying.

GZR_Buffalo

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SHvak cannon
« Reply #16 on: August 26, 2000, 02:20:00 AM »
Sorrow-

I was talking about the continuation war.
And my comment about the use op AP ammo was based on the cases where our planes wre hit by ShVak. The best such case was Eino Luukkanen's MT-201 that was hit by La-5's shells from rear sector. No visible signs of exploded shells, just neat 20mm holes. There happen to exist quite many photos of his plane, taken just after landing. It might be as you say, but then my comment about the quality of Soviet ammo still stays, it was miserable, if none of the shells that hit MT-201 detonated as it seems.

And I beg to differ about 20mm holes making airframe unairworthy. If those holes don't break load-bearing, control, or powerplant structures, you can put awful lot of them on a fighter airfame before the effect can even be felt by the pilot.

If La-5(Fn) and 109G are about equal in level turn, it is the obvious thing for a 109 pilot to evade high, as his plane climbs significantly better even at low altitudes. He can also exploit the fact that his plane has much more gentle stall than La, that is very easy to spin following a stall.

Offline StSanta

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SHvak cannon
« Reply #17 on: August 26, 2000, 02:36:00 AM »
Buffalo:

Also true in Aces High; had a long protracted fight with Nemo in his LA-5. Only chance I could reverse and get a shot at him was dragging him up high and moving on from there.

Probably one of the best 1v1's I've ever had.

<S!> nemo!



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Sorrow[S=A]

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SHvak cannon
« Reply #18 on: August 26, 2000, 04:24:00 PM »
Buffalo:

The plane in question had what? 2 holes in it? not a signifigant amount. And the bullets passed through the skin of his plane and radio, I believe 1 may have imbedded. The detonation of ShVAk was equivilant to any other 20 mm shell- none exploded unless they met enough resistance. Well, expect hispano HE which exploded on contact with anything..  sometimes even air    And I referred to multiple 2 cm holes- more than 2 or three and your odds are toejam poor they won't tumble and start breaking things and detonating. Hell- if the two holes are in a control surface the 109 would probably go down anyway, they splintered badly enough under 12.7mm, 20mm would break them right off!!

As for the tacticals- G2 vs La-5FN is a tight squeak of a fight. and it never happenned in the continuation war. Only scant La-5's were along the border. However- I stay by the same things I said, the La-5 had enough acceleration in experienced hands to speed up under any G-2 in a circle fight trying to climb. At SL their ROC is too similar for a G2 to escape this way unless the La-5FN pilot made an error. in reality- this would be a game of chicken in RL with whoever broke first dieing with two experience pilots flying. and in these cases- the winner told the story because the loser didn't know how to play the game.

Offline SageFIN

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SHvak cannon
« Reply #19 on: August 26, 2000, 05:15:00 PM »
 
Quote
Originally posted by Sorrow[S=A]:


The detonation of ShVAk was equivilant to any other 20 mm shell- none exploded unless they met enough resistance.

Isn't it a known fact that the Soviets did have some problems with factory production in the beginning of the war and also during the later stages. AFAIK they got the tank and plane production lines running hot (20,000 or so Il-2 produced. whew =) but had to rely on lend and lease trucks and halftracks and so on.

And also, the 20mms were very much not equal. First of all each had a different sized explosive charge and all did not use similar explosives. For example the minengeschoss was more effective than many other explosive rounds of same weight.

So, if the Russian explosives were not as good as the ones USA, England and Germany had, then of course it means that the explosive damage caused by the round was not as large as the damage caused by other equally weighted rounds.

 
Quote
Originally posted by Sorrow[S=A]:

As for the tacticals- G2 vs La-5FN is a tight squeak of a fight. and it never happenned in the continuation war.

I would very much like to know where you got the information suggesting that 109-G2 and La-5FN never met during continuation war. I am merely interested in this because if some Finnish sources say that such fights actually did happen, then why aren't the Russian documents (or wherever you got that info of your's) mentioning this and why there is such a difference.

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Sorrow[S=A]

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SHvak cannon
« Reply #20 on: August 27, 2000, 12:26:00 AM »
 
Quote
Originally posted by SageFIN:
I would very much like to know where you got the information suggesting that 109-G2 and La-5FN never met during continuation war. I am merely interested in this because if some Finnish sources say that such fights actually did happen, then why aren't the Russian documents (or wherever you got that info of your's) mentioning this and why there is such a difference.


Quite simply- becuase it was over before the La-5FN went into prototype. There were la-5's that served in very very small numbers along the borders and encountered enemy planes. but this is not an FN version  

The original had almost the same performance of a LaGG-3 of the same time period and was not in the same equivilant as a G-2 (read sharkfood).

As for 20mm I said specifically detonation. The fusing on most 20mm in the war was the same effectivness except for mine rounds and Hispano HE. All had problems with going through planes without detonating. Explosive contents are available in kj on several pages and seem to indicate that mausers and ShVAK were fairly equivilant when they did go off.

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[This message has been edited by Sorrow[S=A] (edited 08-27-2000).]

GZR_Buffalo

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SHvak cannon
« Reply #21 on: August 27, 2000, 03:02:00 AM »
Sorrow,

M-82FN fuel injected engine replaced the M-82F on La-5 production lines at late march 43, continuation war ended at summer '44. G2's were used to the end (and after that) by FAF. I bet they met in the air. And the result was very one-sided, and not in favor of the Russians. In spite of the fact of Russians having huge numerical advantage.

Maybe you are mixing things up with the metal-structure La-7, which replaced the La-5 in production late '44?

One thing about explosives and ammo. If you compare only the energy contents of explosive charges, you will get seriously mislead. There is a property in explosives called brisance, and that determines many of it's destructive capabilities much more than the thermal energy produced. For example, the velocity of a shell fragment does not depend much on the thermic energy, but is almost totally dependent on the velocity of the detonation wave (ie. brisance).

There is all the difference in the word between same weight explosive charges of amatol (mixture of ammonium nitrate and TNT), TNT (tri-nitro-toluene), pentrite (maybe penta-nitro-toluene), hexogen (hexa-nitro-toluene), and octol (octa-nitro-toluene), though I am almost sure no-one had octol in useable quantities during WWII.

Tailslide

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SHvak cannon
« Reply #22 on: August 28, 2000, 01:57:00 AM »

 I came across some info on yak vs 109G armour thought I'd share:

"Me-109G armor is no different from the one on Me-109F, with the exception of the 18 mm plate behind the fuel tank that consists of several sheets of thin aluminum. Its intention is to strip the incendiary mix off the ammunition; it cannot be considered armor, as it does nothing to actually stop the bullet. In addition, as our research shows, the plate does not perform its intended function; on the contrary, it improves the probability of the incendiary ammo setting the tank on fire."

"Armor protects the pilot from attacks from 6 o’clock from 45 degrees high to 35 degrees low. The pilot is protected poorly from attacks from the sides; even with 10 degrees off-nose the pilot is protected only partially. Me-109G2 armor can be penetrated with a medium caliber bullet from 100 meters; a 12.7 mm armor-piercing bullet will cut through it from up to 400 meters.

Cockpit armored glass only protects the pilot from medium caliber ammunition; 12.7 caliber bullets penetrate it easily.

Me-109F fuel tank has enough fuel for two hours of flight. Me-109G2 has enough fuel for one hour of flight at slow speeds. Fuel is used up very quickly at top speeds or during a dogfight; Me-109G will exhaust its full fuel capacity in 40 to 45 minutes. The fuel tank protector mixture (? not sure what the English equivalent is) can fill up to 20 medium caliber bullet holes, and 5 or 6 12.7 mm holes. Incendiary bullet hitting the fuel tank above the fuel level will usually ignite the fumes and cause the tank to explode. Protector liquid does not perform well at low temperatures; during winter the liquid freezes, crumbles and fails to close any bullet holes."

Offline juzz

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SHvak cannon
« Reply #23 on: August 28, 2000, 04:27:00 AM »
"fuel tank protector mixture" = self-sealing.

Offline juzz

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SHvak cannon
« Reply #24 on: August 28, 2000, 04:36:00 AM »
"fuel tank protector mixture" = self-sealing.

GZR_Buffalo

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SHvak cannon
« Reply #25 on: August 28, 2000, 06:54:00 AM »
Tailslide,

All 109's from E to K had the exactly same internal fuel capacity, 400 litres. The endurance on cruise power did not differ significantly between the types, but larger-engined G's and K's had higher fuel consumption under climb/combat power and higher still under WEP power.

The fuel tank in all of them was a L-shaped multi-layer rubber bag encased inside a plywood box of the same form. Also most of the Friedrichs already had the "armored" transverse bulkhead in the rear fuselage just aft the fuel tank.

Offline Vermillion

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SHvak cannon
« Reply #26 on: August 28, 2000, 08:45:00 AM »
Why is it when cannon shell discussion come up, the person on the German side (in this case Finnish with a German gun) always bring up the mine shell?

You would think that a Mauser 151/20 could use no other shell.

If you want an equitable discussion compare shell type to shell type.

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GZR_Buffalo

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SHvak cannon
« Reply #27 on: August 28, 2000, 02:33:00 PM »
Vermillion,

Just simply, because after the mine shell became availabe, nothing much else was used.
Well, some pilots used AP as every third shot in the belt, if the primary prey was IL-2's. The tungsten cored hartkernmunition was used when (rarely) it was available.

Jerries were organized, you know. They at least tried to standardize the ammo production to as few subtypes as possible, and as minengeschosse was clearly superior and did not cost any more to produce, it was only natural, that it became the chosen product.

Of course the minengeschosse really came the favourite with the 30mm MK-108, that was the standard center gun on almost all G-10's and K's. In his book Helmut Lipfert tells about his first test with it. He squirted a short burst into a side of a hill, and was amazed by the result, he tells, that it looked like a mortar bombardment had hit the hillside.

Sorrow[S=A]

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SHvak cannon
« Reply #28 on: August 28, 2000, 08:48:00 PM »
Buffalo: what verm is referring to is the fact that mine shells were almost non-existant on the eastern front. And 30mm? gimme a break- that was anti-bomber ammunition. My Opa was a mechanic during the war and he never even saw 30mm until he came to the western front in the winter of 1944. Planes on the eastern front used standard 20mm with Ap shells when they could get them. Which BTW wasn't as often as you are insinuating.

About kj damage: are you serious? Let me make this clear- if a 20mm shell goes off in a plane brisiance (sp?) means jack toejam. It goes boom and things break- relative power of the detonation in KJ tells us the two were equal enough that it really didn't matter which hit you. If it went off you had trouble. If the KJ values were different then we would be dealing with a serious difference- obviously one would not be using as powerfull an explosive as the other. This is not the case. If we had to deal with hardened steel components or specifical types of damage requirements the quality of the detonation would be important. In a plane it means nothing.

As for the La-7..  no I did not mix that up. The La-5FN was never in active service against finland- if it HAD been the Finns would have fared much poorly than they did against LaGG-3's. AFAIK from data _I_ have seen the only LA's that served on that front were La-5's and later ones with the expanded rear window. The ones with the M-82FN motor went to the German front as finnish front was never as high a priority for such a valuable plane. Hell- at first you needed to be in a guards regiment just to recieve one!

Oh and BTW about this comment:

And the result was very one-sided, and not in favor of the Russians.

Please.. spare me. In the continuation war the Finns did pretty good. But it was by no means one sided. You guys lost pilots too.

Offline -lynx-

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SHvak cannon
« Reply #29 on: September 01, 2000, 07:01:00 AM »
sorrow - you're wasting your breath, the Russians could do nothing that would be considered even acceptable in this argument  .


sageFIN - the Russians worked even harder than you think with over 36,000 IL-2s built.

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[This message has been edited by -lynx- (edited 09-01-2000).]