is the p-40 the best bomber killer?

[il2crashesnfails]

is the damage done by the p40 below higher then say a 190? Seems like it did more damge then cannon

 

 

[Barnacles]

It's weight of fire with 6 fifties is greater than the 190 a3 even with the mg/FF in the wings. 

[il2crashesnfails]

24 minutes ago, 71st_AH_Barnacles said:

It's weight of fire with 6 fifties is greater than the 190 a3 even with the mg/FF in the wings. 

 

i always just thought if it didn't have a cannon it was less powerful

[BubiHUN]

1 hour ago, il2crashesnfails said:

 

i always just thought if it didn't have a cannon it was less powerful

It was less powerful. 

[ICDP]

Weight of fire for 3 second burst tables by aircraft here.  Now weight of fire is not everything because the 20mm cannons also had HE and of course muzzle velocity is a factor.  The P-47 with eight .50 cal MGs has less weight of fire than an Fw190-A4, so the P-40 would have even less.

 

If the calculations are correct.

 

P-47 Thunderbolt
8x .50in mg
9 kg (20lb)

 

P-40E
6x .50in mg
6.75 kg (15lb)

Fw 190 A-4
2x 7.92mm mg
4x 20mm cannon
16.8 kg (37lb)

 

http://progress-is-fine.blogspot.com/2016/04/weight-of-fire-of-wwii-fighter-aircraft.html

[il2crashesnfails]

7 minutes ago, ICDP said:

Weight of fire for 3 second burst tables by aircraft here.  Now weight of fire is not everything because the 20mm cannons also had HE and of course muzzle velocity is a factor.  The P-47 with eight .50 cal MGs has less weight of fire than an Fw190-A4, so the P-40 would have even less.

 

If the calculations are correct.

 

P-47 Thunderbolt
8x .50in mg
9 kg (20lb)

 

P-40E
6x .50in mg
6.75 kg (15lb)

Fw 190 A-4
2x 7.92mm mg
4x 20mm cannon
16.8 kg (37lb)

 

http://progress-is-fine.blogspot.com/2016/04/weight-of-fire-of-wwii-fighter-aircraft.html

 

wow the a4 has 37lb

[ICDP]

Remember that is only calculating the weight of the projectiles and does not include high explosive content.  Regardless both are more than enough to bring down a bomber quite quickly.

[6FG_Big_Al]

I find it hard to decide in this case. In the end, he only landed one strafe run and set the Heinkel on fire.

Likewise, to draw a comparison, you would have to take a Heinkel H6 and try to hit it with 20mm like with the 50.Cals.
But also the question is how many 20s? 4,2 or only 1 ?  
I find these comparisons rather difficult.
 

[ICDP]

It's not empirical but in my Fw190-A5 campaign I found IL2's, Pe2's and Bostons would fold like paper under any decent hits with 4x 20mm.  In my P40 campaign it took quite a bit longer on target to bring down a German bomber.

[Ehret]

5 hours ago, il2crashesnfails said:

is the damage done by the p40 below higher then say a 190? Seems like it did more damge then cannon

 

The P-40s (bots?) in the video did a poor job, really. One got shot down by the bomber defenses and the 2nd wasted most of the burst shooting under the target. Finally, the bullet stream intersected the target and looked like it was about the convergence distance so... yes! It should have high damage and since latest patches condensed hits on engine/fuel tanks will result in fires very often.

[il2crashesnfails]

12 hours ago, Ehret said:

 

The P-40s (bots?) in the video did a poor job, really. One got shot down by the bomber defenses and the 2nd wasted most of the burst shooting under the target. Finally, the bullet stream intersected the target and looked like it was about the convergence distance so... yes! It should have high damage and since latest patches condensed hits on engine/fuel tanks will result in fires very often.

 

I notice fires more often with p40 and p47. is this true or am i just imagining things?

[Ehret]

59 minutes ago, il2crashesnfails said:

I notice fires more often with p40 and p47. is this true or am i just imagining things?

 

I'm not sure what kind of 0.50" rounds we have modeled in the sim but they should carry 1-2g of incendiary per bullet. With that many (6-8x) guns the effective rate of fire will be over 80-110 rounds/s. If you connect your burst on a fuel tank or an engine they are going to burn.

[il2crashesnfails]

32 minutes ago, Ehret said:

 

I'm not sure what kind of 0.50" rounds we have modeled in the sim but they should carry 1-2g of incendiary per bullet. With that many (6-8x) guns the effective rate of fire will be over 80-110 rounds/s. If you connect your burst on a fuel tank or an engine they are going to burn.

 

makes sense!

do you think incendiary bullets have more chance of setting  a tank on fire then say a cannon shell?

[Ehret]

25 minutes ago, il2crashesnfails said:

do you think incendiary bullets have more chance of setting  a tank on fire then say a cannon shell?

 

For the same weapon installation weight cannons should offer a better performance. It's hard to say for certain because cannons shells are much more diverse - just the 20mm Hispano had rounds like HE-Incendiary and Semi-Armor-Piercing-Incendietary among others. It's safe to assume that one 20mm cannon should be equivalent to at least 3 heavy machine guns as a raw damage/incendiary potential is concerned. But it all depends... if your targets were very light Japanese planes then the difference would be smaller. If you were shooting at heavies like B-17 then yes - better to increase caliber(s).

Edited December 28, 2018 by Ehret

[il2crashesnfails]

On 12/28/2018 at 2:36 PM, Ehret said:

 

For the same weapon installation weight cannons should offer a better performance. It's hard to say for certain because cannons shells are much more diverse - just the 20mm Hispano had rounds like HE-Incendiary and Semi-Armor-Piercing-Incendietary among others. It's safe to assume that one 20mm cannon should be equivalent to at least 3 heavy machine guns as a raw damage/incendiary potential is concerned. But it all depends... if your targets were very light Japanese planes then the difference would be smaller. If you were shooting at heavies like B-17 then yes - better to increase caliber(s).

 

I have been told that the germans had to design a less powerful shell in order for it to be able to be fitted to such small fighters such as 109 and 190

[BubiHUN]

5 minutes ago, il2crashesnfails said:

 

I have been told that the germans had to design a less powerful shell in order for it to be able to be fitted to such small fighters such as 109 and 190

Less powerful? Like the 30mm, 37mm 50mm shells? ? Come on

[Ehret]

3 hours ago, -[HRAF]BubiHUN said:

Less powerful? Like the 30mm, 37mm 50mm shells? ? Come on

 

I'm not sure what the poster exactly meant. However, if we compare complete rounds of the MK-103 and the MK-108 then the latter was definitively less powerful. The pro of the MK-108 was reduced weight and smaller size thus could be fit in the 109, indeed.

[il2crashesnfails]

3 hours ago, Ehret said:

 

I'm not sure what the poster exactly meant. However, if we compare complete rounds of the MK-103 and the MK-108 then the latter was definitively less powerful. The pro of the MK-108 was reduced weight and smaller size thus could be fit in the 109, indeed.

 

 

I was also told they reduced the propellant in the shells to protect the fighters frame etc.

This is from a user named "chock" from flightsim.com

 

" In order to get the weapons and ammunition to be light enough and small enough to fit in the diminutive 109, and to not have so much recoil as to cause damage to its fairly lightweight airframe, the Germans opted to use a smaller cannon projectile with a smaller warhead, a reduced muzzle velocity, and a reduced cyclic rate since the gun itself was pared down in size too and could not therefore be kept sufficiently cool with a high rate of fire. "

 

 

So my understanding is :

Sure it very well may be a 30mm, 37mm or 50mm shells BUT they reduce the muzzle velocity and warhead to cater for the fighters frame.

Edited December 30, 2018 by il2crashesnfails

[ZachariasX]

4 hours ago, Ehret said:

The pro of the MK-108 was reduced weight and smaller size thus could be fit in the 109, indeed.

The MK-108 fires 650 rounds per minute, the MK-103 only 440. Fire rate means everything in an aircraft gun. The MK-108 is a far better gun against aircraft, despite its modest ballistic properties.

 

When you rely on blast of the charge in the slug rather than impact energy, then the MK-103 is really an unsuitable gun. It weights twice as much (including ammo) for delivering about 1/3 less punch. This gives the MK-103 significantly less than half as many on board kills than the MK-108 for the same weight, not considering the performance penalty imposed by mounting the big gun.

[Ehret]

33 minutes ago, ZachariasX said:

When you rely on blast of the charge in the slug rather than impact energy, then the MK-103 is really an unsuitable gun. It weights twice as much (including ammo) for delivering about 1/3 less punch. This gives the MK-103 significantly less than half as many on board kills than the MK-108 for the same weight, not considering the performance penalty imposed by mounting the big gun.

 

No! The MK-103 can shot the M-shells as the MK-108... only the complete cartridge is different. The MK-103 as a weapon system is approx 1.17x powerful then the MK-108; the round alone is about 1.7x as damaging. So less efficient but the MK-103 is the more powerful gun; at the least has more powerful cartridges including high velocity Minengeschoss.

[Bremspropeller]

The MK 103 round (not accounting for HE rounds/ M-Geschoss) just makes a hole the same size as the MK 108. No matter if it's going faster or not.

Aircraft primary-structures aren't armored, so the weight of the round is of lesser importance at normal firing ranges.

 

Weight of fire is of little importance.

[ZachariasX]

28 minutes ago, Ehret said:

So less efficient but the MK-103 is the more powerful gun

No use against soft targets as aircraft, as @Bremspropeller said. For air-air kills both 103 and 108 almost exclusively rely on gas pressure damage done by the explosive filler. The 103 round is twice as heavy as the 108 round, giving you nothing of value against soft targets in return. The 108 not only gives you twice the rounds in the same clip, it also lets you fire 1/3 more rounds in the same pass. Nobody that is right in their mind would use the 103 against aircraft if the 108 was available, unless it was for a very select purpose.

[Ehret]

If it goes through an empty fuselage; otherwise difference can be substantial when hitting something like an engine block. The extra velocity of the 103 M-shell wouldn't be wasted anyway; actually it will add (the physical law of the conservation of energy ensures that) to the explosion and that's up to about 80KJ over the 108.

 

The "normal firing ranges" - if you throwing that much HE they better be longer than shorter. Load the 190-A8 with the 108s and shooting at anything becomes two stage "game", already: hit and evade debris. It will get hilarious with the quad 108 arrangement in the 262 - mere seconds to aim; then you shots at very short ranges (bad ballistics) and pray that nothing will hit you in return when you are flying through debris cloud.

Edited December 30, 2018 by Ehret

[Bremspropeller]

18 minutes ago, Ehret said:

actually it will add (the physical law of the conservation of energy ensures that) to the explosion and that's up to about 80KJ over the 108.

 

Nope.

It will just make sure the projectiles of shrapnel will have more kinetic energy (in the original direction of travel).

 

The explosive energy remains the same.

[ZachariasX]

11 minutes ago, Ehret said:

otherwise difference can be substantial when hitting something like an engine block.

True. Butthe engine block is about the last thing you need to touch to make an enine blowing rods.

 

12 minutes ago, Ehret said:

The "normal firing ranges" - if you throwing that much HE they better be longer than shorter.

That is not how it works in practise. There is no sniping with aircraft guns. Distance is set by your ability to set up a correct aim and having to disengage for not picking up souvenirs.

 

In practise, this results in a two second firing window around 300 meters distance from target. The gun that deploys most explosive on the target is the best gun and the 108 is the world beater in this department.

 

Only if the target doesn‘t move (or very, very slowly, like groznd targets), then you have time to line up an attack from great distance and fire from 600 to 800 meters. And for this, the 103 is of course the far better gun with its better ballistic properties. You also don‘t need very high firing rates, as you would fire short bursts anyway. At these distances, the shaking of the airframe will prevent you from hitting anything at these distances.

[Ehret]

1 hour ago, Bremspropeller said:

Nope.

It will just make sure the projectiles of shrapnel will have more kinetic energy (in the original direction of travel).

 

The explosive energy remains the same.

 

The HE material has own weight thus carry KE too and explosion effect is nothing else than molecules at very fast velocities. If you dismiss that then in/out J budget will not check. There is difference between stationary and moving HE; usually is not major but it's there. Even better - it's possible to get an explosion from chemically inert weight only due to the KE; the prime example from nature - asteroids. In the rocketry we have a similar phenomena - the results will depend on the velocity at the moment of burn. Weird because the fuel chemical energy stays the same, but the Oberth effect is real. The faster the stuff go the more you will get from chemical reactions.

 

But what we talking about? The MK-103 is more powerful gun and rounds fired from it have way better ballistics and are more damaging. If you don't agree than relate to the report first, please. That's it isn't suitable for the plane like the 109 is a different issue.

 

1 hour ago, ZachariasX said:

In practise, this results in a two second firing window around 300 meters distance from target. The gun that deploys most explosive on the target is the best gun and the 108 is the world beater in this department.

 

I meant scenario just like that - load the FW-190-A8 with the 108s and do a pass at any target starting about 300m. There will be a shower of debris - it's easy to hit something; especially to lose your prop. Imagine the 262 with 4 108 - debris will be even thicker, chances to evade much lower (high closure rate and high g-loads) and you have a recipe for accident. IRL pilots had similar problems; for Erich Hartmann it was the major combat risk - debris from MK-108 fire.

Edited December 30, 2018 by Ehret

[ZachariasX]

1 hour ago, Ehret said:

load the FW-190-A8 with the 108s and do a pass at any target starting about 300m. 

This is indeed a significant problem when you have the ability blast your mark to smithereens. But this is then again is only an issue when you are parked close behind your mark an let it have it. Like Hartmann that you mentioned. If you go close enough for your target „to fill the entire windscreen“, you are <50 meters from it. A 262 has a closure speed of almost 100 m/s on a bomber, meaning half a second off before... the end of both. Hartmann would never have „parked“ behind a B-17.

 

The cannon is a solution for an attack where you spend minimal time in the other gunners range, hit hardest in a single fast pass and separate.

 

Being fast enough will enable you separating before you reach the cloud of his debris. If the bomber goes 100 m/s, and you starting fire at 400 m with perfect aim, it will have debris starting ~460 meters ahed from you. If you are going 200 m/s, that is >2.3 sec away from you. You can take a one second burst and have 1.3 sec time to alter your trajectory. Doing so, you will have 10 rounds per installed cannon on target, 40 in case of the 262, enough to let any plane have it under almost any circumstances. 

 

That would be a perfect shot. In reality, you‘d maybe start farther out to hose down your mark. Still, you‘d disengage before you‘d pick up stuff.

 

Smaller and AP simply doesn‘t guarantee that. You can shoot 100 AP bullets through a plane without bringing it down. If you hit where there‘s mostly air inside the tin, you‘re out of luck. And there‘s plenty of „just air“ inside a B-17.

[Bremspropeller]

5 hours ago, Ehret said:

The HE material has own weight thus carry KE too and explosion effect is nothing else than molecules at very fast velocities. If you dismiss that then in/out J budget will not check. There is difference between stationary and moving HE; usually is not major but it's there. Even better - it's possible to get an explosion from chemically inert weight only due to the KE; the prime example from nature - asteroids. In the rocketry we have a similar phenomena - the results will depend on the velocity at the moment of burn. Weird because the fuel chemical energy stays the same, but the Oberth effect is real. The faster the stuff go the more you will get from chemical reactions.

 

But what we talking about? The MK-103 is more powerful gun and rounds fired from it have way better ballistics and are more damaging. If you don't agree than relate to the report first, please. That's it isn't suitable for the plane like the 109 is a different issue.

 

What are you talking about?

[Ehret]

20 minutes ago, Bremspropeller said:

What are you talking about?

 

That the MK-103 is a better gun than the MK-108; too much HE causes excessive debris which is dangerous to the interceptor; high velocity is beneficial for the Mine-shells, too.

[ZachariasX]

2 minutes ago, Ehret said:

That the MK-103 is a better gun than the MK-108

Wot? Your posted article says what I am saying, the 108 being about twice as effective as the 103 for shooting aircraft.

7 minutes ago, Ehret said:

HE causes excessive debris which is dangerous to the interceptor

You are very alone with this concern, especially regarding the benefits.

[Ehret]

33 minutes ago, ZachariasX said:

Wot? Your posted article says what I am saying, the 108 being about twice as effective as the 103 for shooting aircraft.

You are very alone with this concern, especially regarding the benefits.

 

The article states 693 units of gun-power for the MK-103, only 580 for the MK-108. Don't change the variable - the MK-103 is the more powerful gun and it's not the gun fault that some cramped air-frames couldn't mount it. For the debris concern no - I'm not alone - Erich Hartmann had numerous accidents because of debris caused by the MK-108 fire. Try the FW 109-A8 with the 108s loaded on any target in the sim - they result in debris shower. It's going to be worse for the 262 because it has 4x 108s and much higher closure speeds. The very slow velocity of 505m/s and relatively light projectile (HE filler is much less dense than thick metal walls of other shells) of the MK-108 don't help ballistics.

Edited December 30, 2018 by Ehret

[ZachariasX]

13 minutes ago, Ehret said:

Don't change the variable - the MK-103 is the more powerful gun and it's not the gun fault that some cramped air-frames couldn't mount it.

With this logic the 88 mm Flak is much much better and it is not its fault that you can‘t mount it.

 

The nominal power of a gun is meaningless. What matters is how much punch you can bring on your target.

[Ehret]

2 hours ago, ZachariasX said:

With this logic the 88 mm Flak is much much better and it is not its fault that you can‘t mount it.

 

A nice fallacy by an exaggeration; we are talking about airborne guns and please stick to that.

The MK-103 remains a better, a more powerful gun - except the cycling rate it has everything better as performance is concerned. It's enough to check barrels and cartridges to see why.

The MK-108 looks like almost as a grenade launcher. The propelling charge of the 108 cartridge is so minuscule it feels weird. It manages only 505m/s with relatively light shell for such big caliber. The HE filler is the only thing the 108' projectile has. If I had to choose just one gun type it wouldn't be the 108... The MK-103 is much more well-rounded and similarly sized and weighted cannons were mounted in the single engine fighters like the M4 in the P-39 and the Sh-37 in the LaGG. Apparently, a heavier cannon like the MK-103 couldn't be mounted in the BF.

Edited December 30, 2018 by Ehret

[ZachariasX]

1 minute ago, Ehret said:

A nice fallacy by an exaggeration

Nope. The MK-103 is too large for most aircraft as well.

 

That the MK-103 is a more powerful gun gives you nothing in return besides longer practical firing range. There will be little practical difference between a hit from a 103 or 108 on a B-17. What it however does, it makes you carry half the rounds to the target. IF you make it to the target in the first place, something the 103 actively works against. Also the long distance sniping is not an option, basically the only thing the 103 brings to the table. You lining up 1 km behind a bomber... well, all the way at the tail of the formations? There, the Mustangs would have a jolly good time with you. In any position other than that one, a hundred gunners would claim having shot you down.

 

The Germans knew why they chose the 108 and did so without much regret. The atricle you posted is also very clear on the subject:

 

The outstanding performer is clearly the German 30 mm MK 108, which achieves ten times the destructiveness of the .50 M2 for only twice the weight. It makes a particularly interesting comparison with the MK 103, which fired the same M-Geschoss projectiles. The MK 103 gains an advantage because of its higher velocity, but loses most of it due to its lower rate of fire, then is finally eclipsed in efficiency because of its much greater weight. No surprise that the Luftwaffe considered the MK 108 their premier air-fighting gun despite its low muzzle velocity. The Me 262 jet fighter, with four of these guns clustered in the nose, completely outclassed the firepower of every other WW2 fighter.

 

I hope you understand that the mentioned advantage of the 103 is reflects the improved hitting ability, not that it supposedly does more damage to an aircraft.

 

So if you are really hoping for more kaboom! upon hitting a bomber with the 103 than with the 108, you‘d be disapointed. Worse, since you‘re dishing out less in the same burst, you create less damage bottom line. Shooting mine shots, the higher muzzle velocity makes aim easier, but it has little effect on destructive power. Adding another 200 m/s directionally to expanding gas that expands with 3000 m/s or so, that does really nothing much.

 

But you can make a nicer hole through the engine block using AP rounds. If, weirdly enough, that would be your sport.

[Guest deleted@83466]

On 12/27/2018 at 2:11 AM, il2crashesnfails said:

is the damage done by the p40 below higher then say a 190? Seems like it did more damge then cannon

 

 

I would definitely favor the 190

[Ehret]

26 minutes ago, ZachariasX said:

Nope. The MK-103 is too large for most aircraft as well.

 

Not nope - the M4 in the P-39 isn't that much lighter (96Kg for the gun + 16Kg for the mag where the MK-103 is 141Kg) and has about the same length. (2.27m for the M4, the MK-103 is 2.35m)

The Airacobra is somewhat bigger and heavier than the BF too which would help to bear the reaction of the gun. The P-39 nose has plenty of free space - no engine which could make things difficult. It was enough for the TP-39 version to have 2nd pilot seat there.

 

26 minutes ago, ZachariasX said:

But you can make a nicer hole through the engine block using AP rounds. If, weirdly enough, that would be your sport.

 

 

Works well enough both in the sim and was historically - engine stops or burns. After the latest updates fuel tanks are valid targets as well. One pass in the P-47D is enough to burn any plane currently available in the BoX with the exception of the IL-2s. Little debris hazard; hits are possible from +500m and can keep firing the whole approach. +400rpg ammo capacity allows for that without much of hesitation. So what weird about that?

 

For the "out-classing" firepower of grenade launchers in the 262 as you said before - only rounds which hit do count and there will not be any B-17/B-24 in the BOBP for some time. Besides, there are diminishing returns and it can be risky to incur more damage than it's necessary for obvious reasons. In fighter vs fighter in the sim practice the quad 108 isn't going to be the best armament except for bouncing unaware. Even so... have you tried the A8 with two 108? If you hit then target disappears in black puffs of smoke and next you see big parts of it flying towards you randomly. Not sure if it's a good option without heavies; better to keep all 20mm - they are safer, have better range and more ammo.

 

Today no one IRL is using 108 like rounds for anti-air and I mean very low velocity with thin walled shells. That was the consequence of the API-blowback mechanism which was necessary to make the weapon and ammunition very light and get high cycling rate. All that to have small fighters to be able to reach and shot down big planes. And... that wasn't enough, still.

[ZachariasX]

8 hours ago, Ehret said:

The P-39 nose has plenty of free space

The P-39 would have been a more potent interceptor if you put the MK-108 in there. It could have carried a lot more rounds of that caliber with the same effect.

 

8 hours ago, Ehret said:

Works well enough both in the sim and was historically -

Historically, I‘d say that the least of all bombers were brought down due to perforated engines. Why would you shoot many small tragets when theres a huge one with soft skin? It wouldn‘t take you more tome to line up and shoot an engine than doing that with the whole bomber?

 

Concerning the sim, I agree, AP are very effective. In the real workd, you wouldn‘t want that. The Germans most certainly didn‘t.

 

The P-47 is not really a comparison here. it has a shotgun requiring to hit something that matters. But with all thise slugs going, there‘s indeed a good chance. But it is a heavy arrangement for that punch. This is why even the Americans were trying to get the 20mm to work. Less weight for the same punch. This also translates into more punch for the same weight.

 

8 hours ago, Ehret said:

Today no one IRL is using 108 like rounds for anti-air and I mean very low velocity with thin walled shells. That was the consequence of the API-blowback mechanism which was necessary to make the weapon and ammunition very light and get high cycling rate.

Firing rate is everything, it was then and it is now. The MG-213 is the grand father of all air-air autocannons. The MK-108 is an older design, but still ingenious enough to make the best trade off for what matters. When you‘re mostly shooting large, armored and lumbering targets (not a Mig-29), then you can sacrifice muzzle velocity for a recoil low enough to not shake off your aim. But the principle is the same: most explosive in the shortest time on the target.

 

With the fast jets today, ballitics is an issue, otherwise there are no hits on the target, so the gun has to be a better performer. Still they are designed for obscene firing rates.

[Leon_Portier]

The P40 is not great at killing bombers, it is too slow to catch up in time with Ju88s and its wing guns are too inpercise to do significant damage.

Best case you surprise the bomber and hit something critical on accident, worst case you are gunner fodder.

[il2crashesnfails]

18 hours ago, Leon_Portier said:

The P40 is not great at killing bombers, it is too slow to catch up in time with Ju88s and its wing guns are too inpercise to do significant damage.

Best case you surprise the bomber and hit something critical on accident, worst case you are gunner fodder.

 

It maybe slow but if it has a height advantage that nullifies that disadvantage.

 

Alot of ww2 planes had guns in wings, Spitfire etc ans they did alot of damage.

 

[=FEW=ayamoth89]

According to this video, is a serious bomber-killer