Why no heavier RAF machine gun calibres?

pbehn said:

Which 50 cal? In 1940 it wasnt what it became in 1943/4. They cause different damage. In 1940 RAF pilots were being struck and damaged by single rounds from 20mm cannon while seeing German bombers sail through hundreds of hits by their 0.303 mgs. Post war it was found that although many bombers didnt go down straight away, they ditched or made forced landings with dead or injured crews, by mid September 1940 what was th most formidable airforce in the world was down to its last 200 serviceable bombers and crews.

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Ki-43's shot down B-17's and B-24's not to mention tough fighters like the P-47 with just two .303's, I bet the RAF pilots would have loved to have replaced their eight British made .303's for two of the Japanese models!!!! Being serious planes from the start of the war to the finish flew home with holes all over them from battle, you only have to look at gun camera footage to see aircraft riddled with fire from all calibers yet break away and escape but only the BoB experience is ever discussed.

A Hurricane that was hit with cannon fire tangling with 109's over France yet returned to base

pbehn said:

Which 50 cal? In 1940 it wasnt what it became in 1943/4. They cause different damage. In 1940 RAF pilots were being struck and damaged by single rounds from 20mm cannon while seeing German bombers sail through hundreds of hits by their 0.303 mgs. Post war it was found that although many bombers didnt go down straight away, they ditched or made forced landings with dead or injured crews, by mid September 1940 what was th most formidable airforce in the world was down to its last 200 serviceable bombers and crews.

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I was thinking of the USA 50 BMG round, the M2 machine gun

Alan Stevens said:

I was thinking of the USA 50 BMG round, the M2 machine gun

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But which variants of those? They changed considerably over time. For example, there wasn't a reliable wing installation for the 50 cal in 1940. Problems persisted with wing installations in US service thru most of 1942.

Same-same for the rounds. The rounds available in 1938-1940 were far less capable than those emerging in 1942-1943.

nuuumannn said:

Punctuation is important for the simple fact that it can be used as clarification of intent. Take this rather innocuous sentence: "Let's eat, children". Take away the punctuation and the intent changes quite a bit...

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Some people already encountered this issue back in ancient times.

buffnut453 said:

Same-same for the rounds. The rounds available in 1938-1940 were far less capable than those emerging in 1942-1943.

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That really gets into a sort of 3 way split. The M8 API didn't show up until late 1943?
The British kept the old type ammo even in 1941 and later (?) orders. US got the M2 Ball and M2 AP starting in late 40 or early 41?
Please note that the M2 in this case refers to the individual type of round and not a series of rounds, there was no corresponding M2 tracer or M2 incendiary or M2 training round the corresponded to the M2 Ball. There may have been M2 tracer or M2 incendiary but they followed their own development path at times there were M2 AP mixed with M1 something elese and no M1 or M2 of a 3rd type available at all.
Each type of ammo may have gotten the higher velocity loading at different times.

Alan Stevens said:

I was thinking of the USA 50 BMG round, the M2 machine gun

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This discussion has been had a few times on here, it seems to take place without reference to date and time. The British were committed to increasing firepower for their fighters from the mid 1930s. Spitfires and Hurricanes had the armament increased early on from 4 to 8 rifle calibre MGs. The Westland Whirlwind was commissioned as a cannon armed fighter, started to be introduced in mid 1940. The Beaufighter was a heavy fighter development o the Beaufort and also introduced in mid 1940. Experiments continued with getting cannon that would work in the wings of single engined fighters, these were unsuccessful in 1940 but by 1941 the 20mm cannon was standard armament on the Typhoon Hurricane and Spitfire. The Spitfire was the only fighter required to work at all altitudes, so it only carried 2, because at high altitudes, with a single stage engine the weight/ drag affected performance. All this was before the USA entered the war with many fighters that only had rifle calibre guns. Some issues with the 50Cal on P-51s were not sorted until around 1943, they didnt concern the gun itself but the mounting and feeding. Late Spitfires deleted the 4 x 303mgs for 2 x 50Cal but by that time the 50 cal was a sorted weapon, and the UK and European theatre was awash with 50cal munitions

pbehn said:

This discussion has been had a few times on here, it seems to take place without reference to date and time. The British were committed to increasing firepower for their fighters from the mid 1930s. Spitfires and Hurricanes had the armament increased early on from 4 to 8 rifle calibre MGs.

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The British were working on the .303 Browning around 1930?
They knew they could not use the Vickers gun in remote locations (where the pilot could not beat on it with gloved fist) and trying to use Lewis guns, even in multiple, was not going to be a long term solution either what with the 97 shot drum.

They had entered into negotiations for the Hispano gun in 1936 and were building the factory in 1938 so any scheme that advances the US .50 cal has to fall well before 1937-38.

This and it's classmates had been built to a 1930 specification with four guns desired.
It just took a while for adjustments to be made and factories built

BTW the British were not dependent on the US for a high power .50 cal machine gun.

Vickers .5in standard, Vickers .5in hi-vel and standard US .50 cal
Vickers had developed the .5in model D machine gun in the late 20s/early 30s.

But it had a few problems, like weight, barrel wear, and low rate of fire. Think long stoke piston in an engine. That long cartridge needed a long bolt travel for each round fired.

Shortround6 said:

The British were working on the .303 Browning around 1930?
They knew they could not use the Vickers gun in remote locations (where the pilot could not beat on it with gloved fist) and trying to use Lewis guns, even in multiple, was not going to be a long term solution either what with the 97 shot drum.

They had entered into negotiations for the Hispano gun in 1936 and were building the factory in 1938 so any scheme that advances the US .50 cal has to fall well before 1937-38.
View attachment 760309
This and it's classmates had been built to a 1930 specification with four guns desired.
It just took a while for adjustments to be made and factories built

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I think I posted mid 1930s. 1930 itself is not mid 1930s and both the Hurricane and Spitfire had their required armament increased in the design and development stage which was in the mid 1930s

pbehn said:

I think I posted mid 1930s. 1930 itself is not mid 1930s and both the Hurricane and Spitfire had their required armament increased in the design and development stage which was in the mid 1930s

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No but the requirement for new guns, instead of the WW I leftovers predated the Hurricane and Spitfire by several years.
When you only have 600hp engines there is only so much weight you devote to guns/ammo. When you get 800-1000hp engines you can do more. But you need (or it is certainly better) to have the guns designed, tested and ready for production when needed.
As is well known the Browning had to be converted to fire open bolt instead of closed bolt to suit British ammo and prevent cook-offs.
Trying to grab the shiniest new toy on the shelf may not work very well in large scale production.

Frugal.