quote:

Originally posted by Bremspropeller:
People are always talking about shooting down bombers...

The Spits also had 20mm right from the Mk IB (when it was indeed a desperate move towards firepower) - but then again, they retained them.

Same with the Tiffie. They fit four of them in there, starting with the IB.

The Japaneese also seemed to like 20mms right early on.

The Spit MKiB was built to intercept German bombers.

Japanese fighters, having flown so far, Had to invoke a feeling of superiority. By again showing that through their skills.

Could destroy. Any US craft. Be it airborn? grounded. Or indeed Seaborn?(I.E. On a carrier.). Being able to destroy the infrastructure that enabled U.S. Aircraft to be able to function.

quote:

The Spits also had 20mm right from the Mk IB (when it was indeed a desperate move towards firepower)

It was to some extent, but the first plans for a cannon armed Spitfire were tendered to F.37/35 (Whirlwind won). In fact Supermarine was told then to -not- proceed so that they got something in the air, ditto Hawker. The Supermarine fighter was seen as more risky as it was more technologically advanced. It wasn't clear at that point how possible it would be to mount 4 cannon in the relatively thin wings of the Spitfire, and some designs of the period (e.g. by Folland, for whom Petter of Whirlwind fame later worked) had the four cannon under the wings in fairings.

Later Supermarine tendered the 323 to F.18/37 and related designs for a twin engined bomber destroyer to be armed with 6 20mm cannon and/or 12 .303s. The Tornado won this, although that morphed into the Typhoon parallel development and the Tornado was cancelled. The Tempest I was almost a revisiting of the Tornado.

But it shows the sort of thing the RAF was looking towards in the mid/late 1930s. In fact the presumption was that for anti bomber work the required number of 20mm cannon was really 6, or a 40mm weapon (cf. P-38 and P-39 with 37mm cannon).

The Whirlwind not being ready for the Battle of Britain forced the bringing forward of the delayed Spitfire cannon plans (despite the specification being 5 years before).

quote:

Originally posted by JSG72:
Hey! Chunkydora.

Sure The P47s 8 gun armament made it a good fighter/Ground attack aircraft.

But Supposing the U.S. Didn't have 4 engined bombers???!!!!! .

You must be drinking stronger juice than me!

The U.S. fighters, would have been facing Jets much earlier.

Go figure?

Seriously. If the US. didn't have 4 engined bombers and only produced erm.. Twin engined bombers. Well.....

A) they would have taken longer to fly accross.
Thus producing less of a threat.
B) They were tactical and would therfore have contributed nothing to the reduction of the German War Machine, production.
C)They would have been bombing France/Belgium/ Holland! And so allowing less migration of Soviet Front fighters to the Western Front.
D) If? The fighters showed a superiority over the then extant 109s and 190s. (Which they would. In numbers.) Jet fighters Heinkel 280 and even the Me 109 TL? with perhaps Nose mounted. 6x mg131s would have been the order of the day?

Hi JSG. I didn't mean to present some kind of alternate reality or anything, just thinking about what decisions the Germans might have made differently if their prop planes could just duke it out with the US prop planes. I wasn't trying to present it in any real historical context or anything.

Good Lord Aaron _GT

You have certaily been Picking whatever you like from Whatever sights you like?

Regardless of what you have "Googled" "Yahoohed" "Jeeved"

Yet again! (And a Human Failing of all those born after 1972? Is the fact that the Internet was not available to those in the 1930/'40s.



BTW. The Whirlwind, has only come to prominence.
Funnily enough. Due to IL2! In my experience

The 4x 20mmcannon armmament was indeed, deemed to be the most efficient. However, As you know? The Tide of War was changing.

With the discovery of the FW. 190. A fighter armmament capable of defeating such a foe. Had to be found? As well as being able to fulfil the new strategey of "Leaning into Europe".

Thus the 2x20mm with an eye on adding 2x.50s was introduced.
OK. So far?

BTW, although I know cannon were good against bombers, mgs must have done something because that's all that was on the Brit hurris and spits in the bob and they shot down plenty of he-111s right?

chunkydora?

Whilst admiring your enthusiasm

I have to call it into question.

Your insistance of subject matter and naivety of WW2 Air warfare. Can only conclude.

That. You are truly a Noob or a Troll in WW2 subjects?

Oh and I am a C**t. And so, say all of us!

quote:

Originally posted by JSG72:
chunkydora?

Whilst admiring your enthusiasm

I have to call it into question.

Your insistance of subject matter and naivety of WW2 Air warfare. Can only conclude.

That. You are truly a Noob or a Troll in WW2 subjects?

Oh and I am a C**t. And so, say all of us!

I protest sir, I protest!

Most emphatically!

A n00b I am not!

I've been getting my *** handed to me since 2003, and have gotten quite good at it.

What subject matter are you referring to? The bob thing?

Why do you conclude I am naive of WW2 air warfare, good sir?

Farewell Mr. C**t. Hope to hear another one of your uniquely punctuated replies as soon as possible! It makes my day!

quote:

BTW. The Whirlwind, has only come to prominence. Funnily enough. Due to IL2! In my experience

I'd agree that the Whirlwind failed to meet the promise hoped for it when tendered to F.37/35. It was too late and the engines were too problematic. It was designed along the lines of the P-38 (.50s and 1 23mm cannon originally intended).

The logic of using a twin was to allow the Hispano to be more solidly mounted than wing mounts, and the Spitfire IB did suffer from jams as predicted. The Hurricane F.37/35 was designed for Oerlikons, so would have been similar to an MG.FF. Never built. Well I suppose the Hispano was an Oerlikon too, if second hand.

quote:

The 4x 20mmcannon armmament was indeed, deemed to be the most efficient. However, As you know? The Tide of War was changing.

With the discovery of the FW. 190. A fighter armmament capable of defeating such a foe. Had to be found? As well as being able to fulfil the new strategey of "Leaning into Europe".

Agreed

quote:

Thus the 2x20mm with an eye on adding 2x.50s was introduced.
OK. So far?

The hope with the C and E wings still seems to have been for four cannon, both wings being capable of carrying them. I don't know if the Mk.24 had (the first mark apart from a relatively small number of VC to routinely carry 4 cannon)

But, just to reiterate, the 4 20mm cannon armament was a good set up and the USA wanted them, but in the absence of reliable cannon then 6 or 8 50 cals were a good compromise, especially from a logistic point of view. In comparison when the British landed on D-day the forces needed four types - .303, 7.92, .50 and 20mm to supply army and air force. I don't know if any P-38s or P-61s operated from France, but if not then it was just .30 and .50 for the ground forces and only .50 for the airforce - much simpler logistics. The US Army was the master of logistics in WW2.

Without a doubt the M2 was better than the .303 Browning the RAF used extensively through the whole war even despite its incremental replacement.

quote:

Originally posted by JSG72:
chunkydora?

Whilst admiring your enthusiasm

I have to call it into question.

Your insistance of subject matter and naivety of WW2 Air warfare. Can only conclude.

That. You are truly a Noob or a Troll in WW2 subjects?

Oh and I am a C**t. And so, say all of us!

A bit surprised you don't recognise the return of a former member JSG72.

Let me give you a couple of clues from a "clueless nub".

He rides a Harley and drives a Dodge pick up.

Hi JSG72,

As to our squabbling and your total awesome amazingness when it comes to knowing everything there is to know about WW2 air combat:

By B16Enk:

"With the in-built offline dynamic campaign/career mode offering immersion only ever experienced before with gallons of whipped cream, and the sisters of St. Olegs Priory (yes there really is a religious order that has sprung from the IL2 franchise and offers succour to it's addicts, some of which is of a spritual nature) a new subset of humanity was created. The flight sim addict. Typified by pale skin, staring eyes, constant over the shoulder looking and mumbles of various o'clocks. Unlike traditional geeks and script kiddies, however, the IL2 junkie knows what a joystick is. Both definitions.

They also commune frequently with others of the same addiction, exchanging pleasantries on UBI Zoo where they vie to out do each other on the IQ stakes. Apparently the prize will go to the one who convinces the judges that they are insufficiently intellectually equipped to operate their trouser zipper in the confines of their bathroom, let alone indulge in attempted sane congress with other intellectually challenged individuals.

Unless of course they are discussing the merits, or otherwise, of a particular war bird. Then, and only then, does any semblance of intellect come to the fore. The discussions can and will ramble on for near eternity with claims of why their currently favoured warbird can perform that starwars maneuver."

I'm sure that your daily schedule looks like this

639 am: get up

800 am be at work at the ministry for understanding WW2 air combat

1230 decide to skip lunch because there are things you STILL don't know about WW2 air combat

530 leave work. pretend to be flying a spit as you honk at the traffic. Mull over you what rather blast that pickup with the 50 cals or go all out and use the 20mms. When he goes 55 in the left lane, wish you had a 37mm.

630 get home. Show off what you know about WW2 air combat at the UBI Zoo.

1130 FLY online

1230 go to bed

This message has been edited. Last edited by: chunkydora,

And he believes he is irresistible to red haired women.

If the USA did not have a working 20mm cannon at the beginning of their involvement in WW2 then it is not hard to understand why they went for a standardized large-caliber MG as the M2. It did its job and it worked within the confinements of the tactical and technical environments it faced. But trying to slap the label of some perceived "superiority" on it just because it was on the winning side stinks worse than rotten fish.

quote:

Originally posted by chunkydora:
I think what Hallion was trying to say was that an uninterrupted stream of bullets (50 cal or 20mm) was more effective (when deflection shooting anyway) than the heavy damage of the guns the luftwaffe used to take down fortresses + the 13mm usually thrown in.

it could be worth to read, what others already posted about changes in the cadence of weapons caused by prop-synching:

quote:

Originally posted by JtD:
For the electrically fused guns the Luftwaffe used that meant a rof reduction of about 5-10%.

5% might be more the optimum, but less than 10% is mentioned quite often in analysis.
for a short summary (although i find some of the tables too general), there is a good comparison of guns and cartridges at
world war 2 fighter armament effectiveness

there the '.50 m2' is rated with an 'efficiency' of 2.1, the 'mg 151/20' with 4.6 and the 'hispano V' with 6 (the exact calulation of the values is explained on the site).
these values take in account (amongst other characteristics) the muzzle-velocity, the weight of weapon and cartridge and rate of fire.
although (as stated there), they lack a factor for reduced rof at synchronised guns - however (see above) it is assumed, that it is less than 10% for electrical fuses.

a last comparison of several fighters is done by listing the time needed to fire an ammunition-power of 2320 (which is what the me-262 did in one second) - having the p-47d (8xm2) at 4.8s, the fw-190a4 (2xmg151/20-synch, 2xmg17-synch, 2xmg151-ffm) at 3.5s and the tempest mkV (4xhispanoV) at 2.3s (the reduction of rof is taken in account in this table).

i have no idea how to consider these tables... most of the data seem to be more or less correct, i am by far not able to say, if the resulting scaling is the same usable. however, the author furthermore brings up some criticism to his calculations and dicusses them in a proper manner.
therefore, i find that tables much more worth to be discussed than the statements of 'ineffectiveness' of cannons compared to the 'concentrated package' of guns by mr. halliot.

quote:

Originally posted by deepo_HP:
world war 2 fighter armament effectiveness

Very interesting, thank for the link!

quote:

Originally posted by csThor:
If the USA did not have a working 20mm cannon at the beginning of their involvement in WW2 then it is not hard to understand why they went for a standardized large-caliber MG as the M2. It did its job and it worked within the confinements of the tactical and technical environments it faced. But trying to slap the label of some perceived "superiority" on it just because it was on the winning side stinks worse than rotten fish.

Well...

.50cals:
1. High ROF
2. You can have lots more ammo
3. If you can hit the target at the right spot and at the right time... they are really deadly
4. Otherwise, the target will be wounded badly, but not killed.

Cannons:
1. Slow ROF
2. Little Ammo (Except for 190s)
3. Deadly if you hit
4. Larger shells are devastating to bombers

So looking at this crude analysis .50s were better for fighter-to-fighter work. High ROF and lots of ammo meant the pilot had more room for error in a dogfight. Good if your escorting bombers. Cannons with slow ROF aren't good for dogfights, but are good for attacking lumbering bombers. With the heavy defenses bombers posed, German pilots needed a weapon that could kill B-17s quickly and efficiently. 30mm cannons were good at that.

So both weapons where better at the job they needed to do.

quote:

Originally posted by WeedEater9p:
.50cals:
1. High ROF

The M2 does not have a high ROF, actually, it has a rather low ROF. The "high ROF" is only true if you have enough of them (6 or 8). In Spifires or Bf 109s, being realively small and light planes, the .50ies would not be very effective, because you couldn't put enough in without seriously hurting performance. In the big American planes, a battery of M2s where an OK alternative.

quote:

Originally posted by Friendly_flyer:
The M2 does not have a high ROF, actually, it has a rather low ROF. The "high ROF" is only true if you have enough of them (6 or 8). In Spifires or Bf 109s, being relatively small and light planes, the .50ies would not be very effective, because you couldn't put enough in without seriously hurting performance. In the big American planes, a battery of M2s where an OK alternative.

..... A "rather low ROF"? Compared to what? The cyclic rate for M2 50s in wing mounts was between 720 and 900+ rounds per minute. To the best of my memory, the only WW2 HMG with a higher cyclic rate was the Soviet UBS.

The P51B/C models carried 4 x wing-mounted M2 50s and were perfectly effective in air-to-air combat versus fighters. The Spitfire was commonly fitted with 2 x 20mms and 2 x 50s in the wings, so it was by no means too small to carry an armament of 4 x 50s.

quote:

..... A "rather low ROF"? Compared to what? The cyclic rate for M2 50s in wing mounts was between 720 and 900+ rounds per minute. To the best of my memory, the only WW2 HMG with a higher cyclic rate was the Soviet UBS.

I’m sorry, I wasn’t very clear. The M2 has a low ROF when you include all MGs in the comparison, including cartridge MGs (typically around 800 rounds/min for the M2, 1200 rounds/min for .30 cal (and thereabouts) MGs). The M2 was on par with most .50 cal HMGs, except as you mention, the Berezin. However, the rate of fire of all the non-Berezin HMGs are rather low, my argument is that you need quite a few of them to be effective.

quote:

The P51B/C models carried 4 x wing-mounted M2 50s and were perfectly effective in air-to-air combat versus fighters. The Spitfire was commonly fitted with 2 x 20mms and 2 x 50s in the wings, so it was by no means too small to carry an armament of 4 x 50s.

The Spitfire was an interceptor rather than an escort fighter, and needed quite a bit more punch than offered by 4 M2s. 6 would be the minimum (and even that would be marginal against a bomber). 6 M2s weigh just a tad more than the late war Spitfire armament (6 M2s weigh 174 kg + ammo, two Hispanos IIs and two M2s weighs 158 kg + ammo). If we are to believe Mr. Williams calculations, you’d need more than 8 M2s to rival the Spitfires firepower, weighing in at 232 kg, and now we are talking weighs that will hit the performance of a plane like the Spitfire.

Despite the M2s many good points, it is not an ideal fighter gun, it’s merely adequate. On the other hand it was reliable (reliability must have been a very important point back then), and more importantly, it was there, with ammo to spare.

I know most will have seen this, but just in case you havent, it explains the exact reason why the .50 cal was retained, and why the USAAF nor the US Navy AF had no real alternative for wing mounted 20mm weapons.

http://www.quarry.nildram.co.uk/US404.htm

(The early Model Hispano was fine when not fitted into wings which bend and warp, and so was fine in the P38/Whirlwind/Beaufighter)

BTW just found this beast, Typhoon with 2x47mm tank busters



Was intended to replace the Hurricane IID's 40mm gun, to give Aircraft a gun to take out the Tiger.