Yak-9T - incredible firepower (or maybe incredible tank's lack of armor?)

[gaunt1]

Perhaps even 20mm AP. Depending on the exact shell type and striking angle, 20mm AP could penetrate up to 60 mm of armor plate:

Impossible with ordinary guns. Thats almost as powerful as a GAU-8 Avenger! The weapon you are referring to is a 28/20mm squeezebore gun, with very special ammunition.

http://en.wikipedia.org/wiki/2.8_cm_sPzB_41

Check the other guns on that site. They are using much larger cartridge than aircraft guns, and their barrel lenght is also significantly longer. (except the Breda).
Even modern 20mm guns are unable to penetrate more than 40-45mm armor:
20mm APDS DM-63 44mm at 1km (1988 )
Bottom of this page: http://collinsj.tripod.com/protect.htm

WW2 20mm guns could penetrate around 10-15mm armor, which is not enough against tanks due to the dive angle.
A Tiger, KV-1, IS-2 should be completely invulnerable, only the 75mm could kill them.

Also, from wikipedia:

In spite of the large round, the VYa-23 proved to be a disappointment in its intended anti-tank role. Light German tanks could be defeated from the side or rear only, with front armor of all tanks impervious. Medium tanks could be defeated if hit into the top of the turret or the engine compartment from under 400 m (1,300 ft) in a greater than 40-degree dive -- a very difficult maneuvre in Il-2 even under the most ideal conditions compounded by the difficulty of aiming at a small target.

And the Vya was far more powerful than any 20mm in the war!

[RPS69]

First of all, in game considerations of ground objects vary a little, but to the effect of calculating armour thickness, they are just two boxes when refered to tanks, and a single box when refered to TDs.

Tanks got front, rear, sides and top armour. Tanks turrets got side the same.
There are not that many hit boxes, only 2!

You can't diferentiate a track hit, a tripulant shot, or an engine disabled by a lucky shot. To the effects of the game, a damaged tank, is a destroyed tank.

Actually that's not so different from actual war, any crew inside a disabled tank in the middle of a battle, will get the hell out of the tank. Disabled tanks on the battlefield, aquire the strange property of being magnetic to lead...

On the guns side, they got a pen table porbability, if low caliber, you require more than one pen to kill the object, higher calibers may kill them with a single shot. 37mm is efective against almost all in game tanks.

Now, the game accept a .50 killing thick armour, if you are capable of hitting them in really big numbers. But it is actually not likely.

TD have allready made ground vehicles far tougher. It is not so easy to kill a light AFV as before TD taking the lead.

So, if a guy could kill so many tanks and armour with a single plane, getting 100% efficiency, they being mostly Pz IVs and less, I will just think it is mostly unlikely to be done without any extras. His aim is far too good. But the pen is perfectly normal for all of them unless he killed them all from the front.

[majorfailure]

Originally Posted by gaunt1

Impossible with ordinary guns. Thats almost as powerful as a GAU-8 Avenger! The weapon you are referring to is a 28/20mm squeezebore gun, with very special ammunition.

http://www.wwiiequipment.com/index.p...kets&Itemid=60
Accordind to this 20mm Hispano was almost capable of this when using special APCR ammo - that in turn had considerable accuracy issues.

Originally Posted by gaunt1

WW2 20mm guns could penetrate around 10-15mm armor, which is not enough against tanks due to the dive angle.
A Tiger, KV-1, IS-2 should be completely invulnerable, only the 75mm could kill them.

That is not entierly correct.
From above source standard AP shot for 20mm Hispano penetrates almost 30mm of plate from ~100m, 0°. For ~350m and 40°, this is about half.

And if I remember correctly BK 37 with APCR penetrated 140mm, 100m, 0°. Even if a 45° shot at 300m does less than half of that it would still punch holes in Tiger I/II (30/40mm top armour) and IS2(25?mm top). And the NS37 should be able to do roughly the same, having somwhat lower muzzle velocity while firing a much heavier shell. So there is nothing wrong with that part of the game IMHO.

Wrong(and changeable) is the every hit is a kill concept because:
-at higher angles there should be a considerable rate of failing projectiles
-not all projectiles that penetrate an AFV result in a kill or even damage, especially if the projectile is of low mass and has low remaining energy

Wrong(and not changeable) is further what human online pilots can achieve:
-hit rates far exceeding that what real life pilots could do, in part because of much better training of players and in part of conditions not simulated(e. g. battlefield smoke or inaccurate projectiles)
-flying maneuvres that would put a real pilots life in danger and the ability to train those maneuvres many times over at no cost besides lots of crashed virtual planes and lots of virtual lifes lost.

[gaunt1]

I dunno. That 140mm sounds unbelievable to me. If you check the link about modern ammunition, you can see that such performance was only possible with APFSDS munition (Bofors). Also, the much larger ZIS-2 AT gun was capable of penetrating 145mm armor @ 500m, with tungsten ammo.

I read somewhere that the reason why the Gemans desperately tried to mount the PaK40 on aircraft was because the BK 3.7 was totally useless against IS-2 and ISU-152 tanks, both with 30mm top armor.

From russianammo.org:

Ammunition used in the NS-37:

BT, AP-T, bullet weight 760g, muzzle vel.: 880m/s, Penetrated 50mm of armor at 200m.

[majorfailure]

Originally Posted by gaunt1

I dunno. That 140mm sounds unbelievable to me. If you check the link about modern ammunition, you can see that such performance was only possible with APFSDS munition (Bofors). Also, the much larger ZIS-2 AT gun was capable of penetrating 145mm armor @ 500m, with tungsten ammo.

Yes, it sounds "fishy" to me, too. But even if it were only 70mm, it should still be barely capable of penetrating the 30mm deck armour at 45°/300m.

Originally Posted by gaunt1

I read somewhere that the reason why the Gemans desperately tried to mount the PaK40 on aircraft was because the BK 3.7 was totally useless against IS-2 and ISU-152 tanks, both with 30mm top armor.

When attacking those tanks from the sides (nice big target, 90° makes shots very likely to acheive results) which would very likely work against T34s, the result would be disappointing. And even if attacked in a 45° dive from above, there would be the problem of ammo disintegrating/bouncing off and also ammo that gets through would lost a real lot of its energy and thus be less likley to do damage.

So a real world pilot firing 30 shots at IS-2, would achieve 6 hits, of these 3 disintegrate, 2 do no damage, and 1 kills an IS-2, while an IL-2 online pilot firing 30 shots at IS-2s gets 15 hits, and all of them kill their target.

Originally Posted by gaunt1

From russianammo.org:

From the same site:
"The AP shells were belt fed and could penetrate 40mm up to an angle of 45°;"
That would make the NS-37 capable of defeating the Tiger Is armor, but not the Tiger IIs armor, at least not regularly.

Originally Posted by Pursuivant

My point was that some types of 20 mm ammo could hypothetically penetrate the top armor of a PzKw or even a Tiger if fired at very close range at just the right angle. But, I think it's quite unlikely and would require a very aggressive, very skilled on-line pilot.

Pz3/4, can be done -with 20mm Hispano. Only needs a high risk approach, 45°+ dive -with lots of training possibly doable on a regular basis.

Originally Posted by Pursuivant

More likely, I think that the armor values for certain late war AFV are crocked, or IL2 overstates penetrating ability of 20mm guns vs. armor, or both.

Nah, I think they are fine. Try shooting up Panzer3/4 tanks with anything 20mm besides Hispanos, there is no fun in that -but maybe I'm not good enough as a pilot.

[RPS69]

Sorry, but IAm a bit confused here. Why do you keep talking about 20mm power when the airplane used bores a 37mm one?

The NS37 if I remeber it well.
I'am a bit surprised to know that it could carry so many 37mm ammo.

But if there is anything bad modeled here, was this canon recoil effects on the little yak.

The same thing applyes to the il2 3m with two 37mm non synchronyzed canons.
Only the first shot could be aimed, on the second shot the plane will be absolutely out of its mark.

[majorfailure]

Originally Posted by RPS69

Sorry, but IAm a bit confused here. Why do you keep talking about 20mm power when the airplane used bores a 37mm one?

The discussion got away from this particular case towards the question if there is a general flaw in IL-2s armour model (either projectiles penetrating deeper than they do IRL or AFVs having less capable armor than IRL).
IMHO there is none, and as an example i mentioned 20mm cannons, that do perform up to specs as far as i tested.

Originally Posted by RPS69

The NS37 if I remeber it well.
I'am a bit surprised to know that it could carry so many 37mm ammo.
But if there is anything bad modeled here, was this canon recoil effects on the little yak.

At least the recoil makes you have to adjust your aim after 1-2 shots, that seems okay to me.

Originally Posted by RPS69

The same thing applyes to the il2 3m with two 37mm non synchronyzed canons.
Only the first shot could be aimed, on the second shot the plane will be absolutely out of its mark.

But it does just that ingame, doesn't it?

[gaunt1]

Yaks have the most realistic FM amongst soviet planes, they are very well modeled. So I think recoil is OK, at least for the "T". Only the NS-45 should have stronger effect, but who cares about that prototype plane?

[Pursuivant]

Originally Posted by gaunt1

Impossible with ordinary guns. Thats almost as powerful as a GAU-8 Avenger! The weapon you are referring to is a 28/20mm squeezebore gun, with very special ammunition.

I agree. A good general rule of thumb is that a WW2 era gun will penetrate mm of armor equal to its mm of bore at 100 m.

My point was that some types of 20 mm ammo could hypothetically penetrate the top armor of a PzKw or even a Tiger if fired at very close range at just the right angle. But, I think it's quite unlikely and would require a very aggressive, very skilled on-line pilot.

More likely, I think that the armor values for certain late war AFV are crocked, or IL2 overstates penetrating ability of 20mm guns vs. armor, or both.