The Effectivness of 8 x.303s

[Colin1]

...there is no mention whatsoever of the US .50 calibre...
Anyone know where this viewpoint would have originated from? Were there any official views that agreed with the assesment?

Waynos (Wayne?)
I have this (typed verbatim)

ALTERNATIVE GUNS
Before leaving this history of the early cannon Spitfires mention must be made of the other armament specified and tested during and before the same period. As long ago as July 1937 the Air Ministry was considering a replacement of the .303 Browning and had issued a memo on the 7th of that month for an ultra high speed gun capable of firing 2000rpm. The memo called for trials with eight of the guns firing explosive ammunition and storage space for 4800 rounds.
Full scale trials took place on 14 December 1937 with the Hungarian Gebauer gun and the effect was likened to a 'welder's torch held against a stressed skin aircraft'. The new gun was intended to replace the Browning five years in the future.
There were problems of course, for increased rate of fire resulted in attendant barrel wear* and increased weight. The suggestion was to drop the ultra high-speed gun and concentrate on a gun with a higher muzzle velocity, which would provide an increased lethal range but the additional velocity entailed a larger powder charge and cartridge.

A compromise in the shape of an armour piercing .276 was suggested.

The Air Ministry took out insurance by asking for designs of two new .303 guns in March 1938 as Browning replacements - the ultra high-speed and the high muzzle velocity. A Blenheim airframe (K7154) was used for firing trials of the high velocity weapon on 9 December but penetration of vital internal parts was insufficient. Blenheim K7041 was also used for the same weapon trials with better results when the gun was fired towards the target's stern.

The Madsen gun was also considered for the Spitfire as a replacement for the .303, this gun was the standard infantry model modified for remote automatic control in an aeroplane.
The calibre was either 6.5, 8 or 11.35mm and the rate of fire increased from 450rpm to 1000rpm and 1200rpm and for this the special recoil spring had to be reinforced. The gun was belt fed and the rounds held together by steel links, this making the task of clearing up the empty belt feed easy compared to the standard gun belt.

A 23mm Madsen cannon was also considered and this too was belt fed with steel interlink and a rate of fire of 400rpm.
The Hispano company also produced a 23mm cannon while Vickers had the 0.5 automatic gun, a 25.4mm, 37 and 40mm cannon. The first had a rate of fire of 450 to 650rpm; the second 100 and the last two 200.

The following is a list of the guns considered for the Spitfire during the design/prototype stage:

Type Weight (lbs) Horiz Range (yards) Feed
Vickers 12.7mm 52.5 4000 belt
Hispano 20mm 83.5 not given drum
Hispano 23mm 88.5 not given drum
Vickers 25.4mm 280 not given drum
Vickers 37mm 600 not given belt
AAC 37mm 235 4375 hopper
COW 37mm 198 not given hopper
Oerlikon FF 20mm 55 not given drum

Another new weapon to come to the Air Ministry's attention was the American 0.5, examples of which arrived in England in June 1940. Drawings were ready the following month and trial installations commenced and by the following August, Supermarine were proceeding with a trial installation of six of the new guns plus a second installation of six 0.5s and 2 x 20mm Hispano cannons (with 120rpg); this being proposed for the Spitfire Mk III.
In the meantime, the 2 x 20mm cannon and four .303s installation had been accepted as the 'b' wing with the result that the 0.5 installations were put on a low priority by 9 December 1940 and the 0.5 eventually being adopted several years later on the Spitfire Mk IX.

*Barrel life for the 0.5 cal was said to be 7-8000 rounds.

Sources
SPITFIRE The History
Eric B Morgan and Edward Shacklady
Guild Publishing
ISBN: 0 946219 10 9
Pages 61 - 62


This of course blows my theory out of the water that they had tested it in the design and development stage but they clearly were considering other weapons besides the .303

 

[Glider]

How on earth were they going to find space for 2 x 20mm and 6 x 0.5?

Excellent Info most of this was new to me.

 

[Colin1]

I think there is one thing we can agree on, implementing (iii) was an error in view of the Spitfires range.

Indeed
it was opposed in very high places
Air Commodore Verney, the Director of Technical Development commented on Sorley's communique:

"As regards the Supermarine F.37/34 I agree that there should be no great difficulty in adding the four extra guns. Deleting the bombs would be a help but I should not be in favour of reducing the tankage as this could be done in production models if required; it is always much easier to decrease than to increase and experience shows that as engine power goes up we often wish to add extra tankage. Nor need the aeroplanes be flown with full tanks"

This sentiment was more or less echoed by Chief of the Air Staff AVM Sir Edward Ellington in a letter to Dowding:

(in his fourth point)
"4. Petrol.
I agree with you that the tankage should be left unaltered, unless it has to be cut down in order to fit in the extra guns"

 

[Colin1]

How on earth were they going to find space for 2 x 20mm and 6 x 0.5?

I have to admit
I was laughing the hysterical laugh of disbelief as I was typing that bit...

 

[Colin1]

Oh
apologies to all for the way the table turned out
It seems I still can't do tables in vBulletin...

 

[HoHun]

Hi Claidemore,

Could you please use a different quotation style? Since the forum engine does not automatically copy stuff in quotes, I can't see your text once I answer. I could copy it manually, but since you did not add any characters to mark what's your text and what's mine, that would still leave me without basic information on what you wrote. You also added some text behind the closing quote bracket so you're not even consistent within your method which requires me to spend even more effort into sorting the mixed quoted and new text.

>I 'm not convinced that the .303s used in BoB were ineffective or that the Battles eventual outcome hinged heavily on their use.

You have to realize that "effective" is not a yes/no question. Effectiveness is a scalar, and more is better. The "eventual" outcome of the Battle of Britain was a British victory, but victories are not all the same either. Using 20 mm cannon the RAF could have achieved a much better victory with less damage done to the RAF defense infrastructure, fewer British fighter pilots lost, fewer RAF aircraft destroyed, less damage to British cities and fewer civilian casualties. Obviously, all of that would have been beneficial for Britain, so I don't see how anyone can seriously propose that all was right with using 7.7 mm machine guns just because the Battle of Britain was eventually won.

>The numbers shot down show quite clearly that they were vulnerable to .303 fire.

You don't know the number the RAF could have shot down with 20 mm cannon, so the number of bombers shot down doesn't tell you anything about the quality of the 7.7 mm machine guns.

>Between 1500 and 2000 aircraft shot down in 3 months. That makes 'poor' a very relative term.

If it takes 3 months to shoot down 1500 to 2000 aircraft with 7.7 mm machine guns but just 1 month with 20 mm cannon, you'd still have to call the machine guns "poor". It's not like winning the Battle of Britain was a piece of cake for the RAF or only Luftwaffe aircraft got shot down in those 3 months.

>True, but was the decision made because of the damage from German cannons, or from poor defensive armament and lack of long range bomber escorts? I don't see a way to quantify that outside of an educated guess.

The German bombers had no better defensive armament than the Wellingtons that were blasted out of the sky over the North Sea, and the Battle of Britain showed pretty clearly that the Luftwaffe did not have competitive long range bomber escorts either. Besides, there can be no doubt that the German losses would have gone up over Britain had the RAF fighters had cannon, so it's not difficult to understand the impact better firepower would have had on the Luftwaffe.

>The Luftwaffe was forced to go to night bombing, and it was forced by 8x303 armed Spits and Hurricanes.

Suffering heavier losses to cannon-armed fighters, the Luftwaffe would actually have been forced to go to night bombing earlier, which would have reduced the amount of damage they could do to fighter command and other important British targets as the accuracy of night bombing was considerably worse than that of daylight bombing.

"Victory" is no more a yes/no affair than "effectiveness", and it's pretty obvious that the RAF victory in the Battle of Britain could have been improved upon if the RAF had had a more effective weapon than the 7.7 mm machine gun available for their fighters.

Regards,

Henning (HoHun)

 

[Waynos]

Colin, thank you for that info, it was most enlightening. Clearly the work was done then so that means, in relation to my question, either Flight and the Aeroplane just ignored it, or, probably more likely given the standards of the aviation press of the time, it was all top secret and they either didn't know or weren't allowed to say.

Regarding the spacing of the 8 guns, I am given to understanding that Mitchell, Shenstone and Smith always found it unsatisfactory, much preferrring the Hawker 'battery' but, according to Shenstone, it was the only way the wing could be kept so thin and retain the required strength.

Henning, I see what you are saying but isn't that a bit too 'what if'?

The only alternative gun available to the RAF at that time was the 20mm, and those aircraft that had it constantly suffered jams and the Sqn Ldr even asked if they could go back to 8 .303's, on that basis, faced with jamming cannon or no ammo for the .50's, surely it was the right armament for that particular short space of time?

 

[HoHun]

Hi Waynos,

>Henning, I see what you are saying but isn't that a bit too 'what if'?

I have not suggested that the RAF actually could have employed any other battery than they historically did.

However, when talking about the effectiveness of the 7.7 mm battery of the RAF fighters one inevitably has to compare it to other contemporary batteries, and clearly a cannon battery would be advantageous.

And a firepower advantage applied in combat would inevitably translate into other advantages ...

There is nothing wrong with considering possible alternatives when assessing historical facts - if it looks like a "what if" here, that is just because it seems necessary for me to illustrate the cause-and-effect chain the historical decision triggered.

Regards,

Henning (HoHun)

 

[Colin1]

However, when talking about the effectiveness of the 7.7 mm battery of the RAF fighters one inevitably has to compare it to other contemporary batteries, and clearly a cannon battery would be advantageous...

...There is nothing wrong with considering possible alternatives when assessing historical facts

I tend to agree
when asked the specific question that this thread asked,

8 x .303s were seen to be adequate ergo cannons couldn't have done any better

the existing armament would have to be benched against an alternative which can by definition only be a what-if; the original question even provides us with the what-if alternative - the cannon.

 

[Waynos]

Yes quite. In regard to what you are saying I am reminded of a book I read recently (but infuriatingly I can't remember the title - maybe the following will ring a bell for someone?) which seems to demonstrate from the historical record that the Air Ministry agreed with you completely.

The Air Ministry, in a series of memo's, showed that they regarded the Spitfire as obsolete as early as 1939 and it was being asked whether Supermarines might not be more gainfully employed producing Whirlwinds or Beaufighters instead. This was clearly not driven by performance considerations and so I am left to surmise that it had everything to do with those two types being armed with 4 20mm cannon, the only two British fighters that were at the time.

Have you heard this?

PS, I found the very book as I type! it is 'Spitfire-Portrait of a Legend' by Leo McKinstry

edit; there were also grave concerns over production delays, here is a quote I like from early 1938

"The Prime Minister says the Spitfire is the fastest fighter of any country in the world, but it is not in the service of any country in the world, this is one of our complaints'

Here is one of those I was referring to earlier, it was written by Deputy Chief of Air Staff, AVM R E C Pierse on the subject of awarding Fairey a contract to build Spitfires;

"I would most strongly like to press that Faireys should build the Westland fighter, it would be a mistake to give Faireys an order for an obsolescent type when they have the design staff to produce a better type' then adding 'The RAF needs a cannon fighter and the Westland machine is the answer'. This was dated July 1938, even before 19 Sqn had the RAF's first Spitfires!

Later in November 1938 Sir Cyrill Newhall expressed his regret that that RAF had no cannon fighters and express his view that when it was up and running the Nuffield factory should be given over to building the Westland type (obviously both these quotes refer to the Whirlwind)

 

[Colin1]

The Air Ministry, in a series of memo's, showed that they regarded the Spitfire as obsolete as early as 1939 and it was being asked whether Supermarines might not be more gainfully employed producing Whirlwinds... ...it had everything to do with those two types being armed with 4 20mm cannon, the only two British fighters that were at the time.

edit; there were also grave concerns over production delays, here is a quote I like from early 1938


Here is one of those I was referring to earlier, it was written by Deputy Chief of Air Staff, AVM R E C Pierse on the subject of awarding Fairey a contract to build Spitfires;

"I would most strongly like to press that Faireys should build the Westland fighter, it would be a mistake to give Faireys an order for an obsolescent type when they have the design staff to produce a better type' then adding 'The RAF needs a cannon fighter and the Westland machine is the answer'. This was dated July 1938, even before 19 Sqn had the RAF's first Spitfires!

Wayne
the Whirlwind and its fate almost merits its own thread, but a potted post-mortem here pretty much corroborates what you say:

1. Failure to control requirements
2. Failure to give an early production order
3. Failure by the manufacturer to produce on time
4. Failure by the manufacturer to accept the need for improvements, and quickly
5. Failure of the engine manufacturer to have a developed engine
6. Failure by the MAP to ensure mass production of the aircraft
7. Failure by the Air Staff to foresee the possibility of the design (?)
8. Failure by Fighter Command chiefs to see the potential in the design, mainly because of the 'single-engined fighter complex'

Vacillation on design requirements and wrong decisions in regard to ordering fighter aircraft in regard to ordering fighter aircraft for the RAF did not finish with the Whirlwind, this extended even into post-war years when Air Staff seemed to have difficulty formulating their requirements.

Sources
WHIRLWIND The Westland Whirlwind Fighter
Victor Bingham
Airlife
ISBN: 1 85310 004 8
Page 134

 

[Vincenzo]

The source specifically states " Luftwaffe forces deployed against Great Britain, Aug 10 1940. Figures taken from the Luftwaffe Quartermaster General 6th, Abteilung returns."
Slaterat

i find where take the numbers, not from quartermaste general 6th, that it's for june, but from a Luftwaffe orbat for 13 august the total it's for all 109s versus england incluse that of nachjagd (only 33), that are numbers for strenght not for serviceable planes, this are 771 for tagjagd e 21 for nachjagd

 

[Watanbe]

Well in the BoB for the Spitfire the 8x .303 was the best combination, reading Douglas Bader's book the general school of thought was that the Pilots thought the cannon armed Spitfires were inadequate compared to the .303 armed models!

For the Me109 the armament of 2 cannons was probably more effective than equipping that plane with .303 machine guns!

 

[HellToupee]

8 303s are perfectly fine when the only alternative was a cannon that just was not ready as we saw in the mk1b.

The germans hardly had a big advantage ither, their cannon was the MGFF its firerate and muzzle velocity was low like a mk108, it was badly matched with the MGs in the nose.

 

[Marcel]

Well in the BoB for the Spitfire the 8x .303 was the best combination, reading Douglas Bader's book the general school of thought was that the Pilots thought the cannon armed Spitfires were inadequate compared to the .303 armed models!

For the Me109 the armament of 2 cannons was probably more effective than equipping that plane with .303 machine guns!

Actually Standford Tuck and Bader fought quite a bit over this. Tuck being advocate for heavy canons and Bader for the 8 .303's. Tuck's idea about the armament was quite different and he says most of the pilots supported him. Just pick who you want to believe

 

[Glider]

Bader was well known in his preference for the 8 x 303 over the cannon/mg mix. If I remember correctly he initially flew a Spit Va instead of the Vb used by the rest of the unit.

I read a comparison report between the 109f and the Spitfire, where the Germans considered the Cannon armed Spitfires to have considerable firepower. Ironically it was an appendix in a book detailing who actually shot down Bader.
The chapter leading up to this was a comparison over the interview techiques used by Germany and Britain when interviewing captured pilots. The comparison paper was based on what was found out by concentrating on a pilot. The pilot in question was one of the first 109F pilots to be captured and the British were keen to find out all they could. Most of the information was obtained by bugging his room and putting another German Pilot in with him who liked to discuss aircraft.
In short the Germans were delighted with the 109F and felt that it had the edge in performance over the Spitfire even being able to turn inside the Spitfire with the exception of the new cannon armed versions. Metal tabs possibly.
But they bemoaned the lack of firepower presumably an F2 and considered the cannon armed Spitfires to be very well armed as he had seen two 109's disintigrate when hit by the cannons.

If anyone is interested the book concluded that Bader was shot down by another Spitfire

 

[Waynos]

If the rest of Bader's squadron had 8 mg's instead of cannon maybe he could have made it home?

 

[Watanbe]

From what I understand of him getting shot down didn't he make an ambitious attack on two 109's and get jumped, or something similar?

 

[Glider]

If the rest of Bader's squadron had 8 mg's instead of cannon maybe he could have made it home?

Its more likely, that if the rest of the Squadron had 8 x 303 he may well have survived.

 

[Glider]

From what I understand of him getting shot down didn't he make an ambitious attack on two 109's and get jumped, or something similar?

To be honest I don't remember much I was caught in a heavy downpour without a coat and dived into a boom/coffe shop until the rain passed. So I didn't read all the book just the bits that interested me.