Impact of fully adopted and reliable 20mm in BoB

[The Basket]

Now this is the RAF I know.

Some loonpot screaming..."I don't care about 20mm cannon! I want my four 20lb bombs!!!!!"

Had them at Ypres, old boy.

 

[buffnut453]

Now this is the RAF I know.

Some loonpot screaming..."I don't care about 20mm cannon! I want my four 20lb bombs!!!!!"

Had them at Ypres, old boy.

Bring back the Brisfit, too. Oh, they tried to...it was called the Defiant.

Hmmm...got to love it when we learn entirely the WRONG lessons from history.

 

[XBe02Drvr]

Why was the Spitfire needed to carry 4x20lb bombs? Sink Graf Spee?

No, it was to comply with the ordnance standardization requirement of Aurora Plastic Models, of course! It had to match the FW190, Me109, P40, Zero, and P38, didn't it? Can't be giving anybody any unfair advantages, can we?

 

[MikeMeech]

Now this is the RAF I know.

Some loonpot screaming..."I don't care about 20mm cannon! I want my four 20lb bombs!!!!!"

Had them at Ypres, old boy.

Hi

From the Spitfire Vc the RAF had cannon and bombs, although not 20 lb but either two 250 lb or a 500 lb, so the RAF got both. It did take the RAF a little while to get back to fighter-bombers during WW2 (1941) which had been well used by the RFC/RAF during WW1.

Mike

 

[The Basket]

Not saying Spitfire shouldn't have ground attack but certainly saying that 20lb bombs are hardly ground attack.

I learnt something so happy with that. Didn't know about the specification to load 20lb bombs.

When did Britain move away from the firing through the propeller arc? It was very much vogue so odd Spitfire missed that train.

 

[XBe02Drvr]

When did Britain move away from the firing through the propeller arc? It was very much vogue so odd Spitfire missed that train.

Well it looks like the original "stuka" Spitfire had its guns synchronized through the prop, so that kind of dates it, doesn't it?

 

[buffnut453]

When did Britain move away from the firing through the propeller arc? It was very much vogue so odd Spitfire missed that train.

Gladiator was the last RAF fighter with guns firing through the prop arc. As guns became.more reliable, there was no need for the pilot to have access to them to clear stoppages etc. The Hurricane was the first of the new breed of modern fighters with guns entirely separated from the pilot.

 

[stona]

Gladiator was the last RAF fighter with guns firing through the prop arc. As guns became.more reliable, there was no need for the pilot to have access to them to clear stoppages etc. The Hurricane was the first of the new breed of modern fighters with guns entirely separated from the pilot.

As the Hurricane was being designed the only option available was the Vickers machine gun. It was notoriously unreliable, and one of the reasons it was thought necessary to keep it within reach of the aircrew. The Gunnery Section of the A&AEE ascertained that the problem was exacerbated by the use of 'wide-tolerance' WW1 ammunition. There were millions of rounds in storage and no prospect of producing anything else until this was used.

By coincidence retired British naval officers were on secondment in Japan with the Imperial Navy and reported to the Air Ministry on Japanese comparative trials of six contemporary machine guns. The Vickers came last, and by a long way.

The British seem finally to have realised that they had a serious issue with armament for their aircraft and in 1933 (?) an Armament Research Division was established at the Air Ministry. To cut a long story short, the British now carried out comparative trials of a number of machine guns (definitely in 1933) and the American Colt won by a country mile. Enquiries were made of the company as to whether the gun could be adapted to use the British .303 'wide-tolerance' ammunition rather than the .30 calibre rimless ammunition for which it was originally designed without compromising its high rate of fire. In January 1934 the Air Ministry received confirmation from Connecticut that this could be done and the rest, as the saying goes, is history. The Colt was considered reliable enough to be positioned away from the pilot/aircrew and this was an important step in increasing the number of guns from the two (or maybe four) which could be mounted on the fuselage, firing through the propeller arc.

 

[The Basket]

Can you specify because the Vickers is considered a good ground gun So this test is as an airborne weapon?

 

[Greyman]

This was the Vickers Mk.V gun meant for aircraft, not the old Mk.I that served the Army into the 60s.

 

[Shortround6]

The Vickers is one of those guns that shows the difference between durability and reliability.

It was extremely hard to break a Vickers gun. However the manual listed something like 27 different jams/ stoppages, most of which could be solved by a good thump and an energetic hand on the cocking handle. Which is why they liked to mount them where the pilot/crew could get at them. Manual is even supposed to have a diagnosis for most of the jams/ stoppages based on the position of the cocking handle. If handle stops at position xx then yy is the likely fault and zz is the best corrective action.
Ground gun had several men in the crew and even a few common parts breakages could be solved in short order with the parts kit.
Even ground Brownings came with a parts kit. Firing pin, extractor and a few other minor but important parts.

Airplanes and ground troops had different requirements.
An aircraft gun needs to be able to fire 300-1000 rounds without very many stoppages. But might have a life of only several thousand rounds before needed overhaul or replacement.
The ground gun can have more stoppages but needs to last many thousands if not tens of thousands of rounds before overhaul/replacement.

 

[The Basket]

So getting a 303 machine gun had to be planned and organised in 1934 and we had to ask America nicely.

So we could have had Type 224 with Vickers fighting the BoB!

So not having 20mm don't seem bad.

The idea of reliability is obviously based on what reliability means.

I believe that in ww1 the odd stoppage and quick fix would have been a more annoyance than a game changer.

From what I read the Vickers ground gun could fire rounds all day long. So it's quite a thing to call it unreliable.

I guess a minor jam and firing pin snap are both stoppages but very different in resolution. With SA80 testing I know that minor jams were not called stoppages so only show stoppers were. So the SA80 would appear more reliable than it actually was.

Machine gun crews would have ate and breathed Vickers so a minor stoppage would be fixed in an instant. So would be more par for the course rather than a heartbreaker and maybe not even considered a stoppage more a quirk of the gun.

British 303 ammo was more rat grade than factory spec in ww1 so it must have plagued hell on machine guns. No big deal if the SMLE and Vickers ate it up but certainly did the Ross no favours

Maybe this is where the stoppages lay.

 

[PAT303]

Airplanes and ground troops had different requirements.

The one thing that plagued ground guns that were fitted to aircraft was the belt feed, the various .30's and later the .50 was they worked perfectly fine if fired with the plane flying straight and level but as soon as G was added it forced the guns to either choke or not chamber depending on the direction of turn, the Hispano had the added problem when fitted to the Spit of being fitted to a wing that was designed to twist to help stall control which it didn't care much for.

 

[PAT303]

British 303 ammo was more rat grade than factory spec in ww1 so it must have plagued hell on machine guns. No big deal if the SMLE and Vickers ate it up but certainly did the Ross no favours

I will disagree here, all regulation .303 ammunition was made to factory spec's, I have heaps of it made over many decades and manufacturers and it's all very good quality, so good I have reloaded thousands of ex-mil cases until I could no longer source .250 thou berdan primers so I reamed the pockets out to accept shotgun primers, many of the cases were made back in the 1940's and I still use them today, the only bad stuff I have had is modern S&B and every American brand which is all undersize, especially rim thickness and rim to shoulder length. The Ross rifle jammed because the rear locking lug doubled as the bolt stop, when used in anger the lug deformed causing it to no longer being able to engage in it's recess and seizing the gun.

 

[PAT303]

The Vickers is one of those guns that shows the difference between durability and reliability.

When it worked it worked, even if it didn't get to 1 million rounds. The Great Machine Gun myth ?

 

[MikeMeech]

S

British 303 ammo was more rat grade than factory spec in ww1 so it must have plagued hell on machine guns. No big deal if the SMLE and Vickers ate it up but certainly did the Ross no favours

Maybe this is where the stoppages lay.

Hi

The rapid expansion of war industry in Britain to get the quantities of munitions needed did cause problems in quality and all the way through the war some factory's quality was better than others. This led to ordering from factories abroad, however, this did lead to even poorer quality ammunition arriving in the UK. Around about 50% of the .303 ammunition produced in the USA was regarded as "suitable for emergency use only, and much was sentenced for practice at home." by the War Office. The companies concerned, 'Remington Arms Union', 'National Cable and Conduit Company' and 'Peters Cartridge Company' (this company appears to have been the 'best' quality out of them), they were also well behind in deliveries and cost more than the ammunition produced in Britain. These are some of the main reasons that American contracts were cancelled on 17 October 1916. In 1917 a stock take of 'salvaged' ammunition at Woolwich and much of it was found to be American produced, the Supply Department stated "apart from Peters, American small arms ammunition has so many faults that it will probably not be worth while to try and recap any of this ammunition", indeed it appears it had such a bad reputation that if ammo boxes were opened and it was found to be American it would be thrown to one side "as useless". (Information from 'The Official History of the Ministry of Munitions' Volume XI 'The Supply of Munitions').

However, this did not mean that British ammunition was of good quality for aircraft use and measures were taken to improve this:

"...the British introduced in 1917 'Green Label' (or 'Green Cross') .303 ammunition specifically for synchronised guns. This was taken from standard production lines, but carefully selected from batches which complied with tighter manufacturing tolerances and gave reliable ignition. This proved successful and was followed up in 1918 by establishing special production lines to make high quality ammunition for this purpose. This was known as 'Red Label' (also as 'Special for RAF, Red Label', Special for RAF' and finally 'Special')." (Info from 'Journal of the RAF Historical Society, No. 45' 'The Development of RAF Guns and Ammunition from World War 1 to the Present Day' by Anthony G Williams).

We can see that attempts were made to improve the ammunition for air use.

Mike

 

[The Basket]

I remember reading in a magazine about a horsepower test on brand new Honda Fireblade motorcycles and there was a 9 bhp difference between best and worst.

9! And this was Honda in Japan in the modern era!

So quality control of ammunition in 1914 under wartime pressure must have been an absolute clown infested circus.

Mausers and Type 38s were deliberate designed to not explode when cartridges rupture so quality control and tolerance of ammunition by today's standards and 1914 standards are night and day.

Machine guns don't do well with poor ammunition.

I am interested in the idea of the airborne Vickers been unreliable so that would be interesting reading although it was the standard British air power gun. So it cannot have been that bad.

I assume the unreliable Vickers is the Maxim one and not the Vickers K.

 

[Greyman]

'Reliable' as a blanket term probably shouldn't be fixated upon in this case.

It would appear the 'aircraft Vickers .303' (Mk.IIa, III, V) was reasonably free of stoppages that couldn't be cured quickly with a quick-acting human appendage.

Once you remove that latter variable, the Vickers stoppage rate appears to have been well behind the competition available in 1934.

 

[Shortround6]

I am interested in the idea of the airborne Vickers been unreliable so that would be interesting reading although it was the standard British air power gun. So it cannot have been that bad.

I assume the unreliable Vickers is the Maxim one and not the Vickers K.

In the 20s and early 30s nobody really had anything much better (US excepted) but in the 30s a number of nations started working on new guns to replace the WW I leftovers.
Let's also remember that the aircraft Browning is a variation of the M1919 air cooled gun which was a variation on the M1917 water cooled. Which puts it 10 years or more newer than many other aircraft guns used during WW I or in the 20s.

The Vickers K gun was developed from the Vickers Berthier machine gun : Vickers–Berthier - Wikipedia

and the design was not suitable for belt feed (at least not without a lot of work).

It may have seen more use in the Indian Army than the Wiki article suggests during WW II.

 

[The Basket]

Also it was designed by Browning.

Sweet Moses himself.

That got to be 10/10 on the god tier scale.