Why did the RAF persist with the .303 throughout the war? (1 Viewer)

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Never understood why Mossies and Beaus carried MGs I mean if you cant knock down a plane with 4 x 20mm Hispanos, then 4 or 6 .303s arent going to do it.
 
Standardisation of calibre with small arms also seems logical, but the Aussies used Lee-Enfields and Brens too, yet they still chose to put HMGs on their Beaufighters. Maybe it was a case of, if it ain't broke don't fix it, like the USAAF sticking with the .50 because going with cannon would have been a major hassle for extra firepower that wasn't really needed anyway.

Where were the Aussies getting their machine guns and ammo from?

I don't think there was an Australian factory for .303 Browning guns. By 1942/43 the British were using pretty much all AP and Dixon/De Wilde ammo in their fighter guns and the bombers where using a heavy mix also. While Australia did make .303 ammo it might have made sense for them to make ammo for the ground guns and just get .50 cal guns and ammo from the US. The US was closer and was supplying a lot of other needs anyway.
 
This one has doubtless come up before, but what the hell. By the end of the BoB it was - from all accounts - pretty obvious that the Browning .303 lacked the firepower to reliably deal with increasingly tough LW fighters and bombers. The Hispano 20mm proved the answer. Yet the Browning persisted in conjunction with the larger gun on Spitfires, Mosquitos and Beaufighters. Why? Wouldn't ditching the Browning for half as many .50s or a couple of extra cannon have made sense? Or was there something about the way lots of small projectiles complemented the explosive cannon shells that that made the combination more than the sum of it's parts?

The USAAF and USAF persisted with 0.5 in MG for several years after every other service had decided it lacked the firepower to deal with modern aircraft; the RAF probably kept the 0.303 in for the same reason: inertia. For the turreted installations, it was probably lack of an acceptable alternative and perceived lack of effectiveness of bomber defensive armament, especially at night without any sort of radar assistance.
 
It really is astounding the strange stuff, at times, which is written on this subject (how, on earth, could you fit the non-existent Aden 30mm into a Spitfire wing?); the RAF did not go for a spread pattern, in fact I have a copy of the harmonisation diagram, for the Vc (which would also have held good for the VII, VIII, IXc, and XIVc until war's end,) which was to be set up at a range of 50 yards, and concentrated the aim of all guns, camera, and gunsight at 250 yards.
The Air Ministry (not the RAF) stayed with the battery of 4 x .303" (in the teeth of opposition by Leigh-Mallory) because it was felt that, in a deflection shot (at which, in general, pilots were not very good,) the four guns had a better chance of disabling the enemy pilot, who had little, or no armour at his side, than two slower-firing .5". It had also been found that the .5" was no better at penetration of German armour, in astern shots, which didn't help. And, I'm sorry, Pinsog, but RAF pilots were not "relatively untrained"; "aiming-off" "deflection shooting" call it what you will, takes a certain skill, which not everyone can master, and the likes of Tuck, Johnson, Bader, etc., used to go duck-shooting to hone their skills, something that was not always available to the ordinary pilot.
When the gyro gunsight appeared in 1944, it changed things completely, since it virtually guaranteed that pilots would hit what they were aiming at, and that was when the Air Ministry finally allowed usage of the .5".
 
By your reasoning, had allied aircraft been armed exclusively with cannon by 1944, the Germans would have responded by stripping all the armour from their fighters. A little counter-intuitive, to put it mildly

I agree that the reasoning is weird, but that was just what Finnish Air Staff ( who were pretty inept people, IMO) did.
In 1943 they learned that the seat armor of the Curtiss fighters were inadequate stop 7.7mm AP round from close range.
Solution: Order to remove the seat armor.
 
And, I'm sorry, Pinsog, but RAF pilots were not "relatively untrained"; "aiming-off" "deflection shooting" call it what you will, takes a certain skill, which not everyone can master, and the likes of Tuck, Johnson, Bader, etc., used to go duck-shooting to hone their skills, something that was not always available to the ordinary pilot.[/QUOTE]

I have never read anything about how well British pilots were trained until coming to this forum. My information came from several other discussions on the BoB and various armament discussions right here on this forum, where several well informed people (they seemed well informed to me at the time) stated that many British pilots at the time of the BoB were relatively untrained, especially in the area of air to air gunnery skills, having little to no training at all before being thrown into combat. The reason stated was that the RAF had already lost many of her trained professional pilots over France and they were being replaced with men whe they hadnt had time to properly train. Later on the training caught up and they were among the best in the world. This was given as one of the many reasons they stuck with the 303 over other slower firing but more powerful weapons and to make up for the lack of power of the 303 and the lack of gunnery training of the pilots, they got in REALLY close to the bombers. I only recently read that they didnt concentrate all of there weapons into a small area, which was a huge suprise to me. I would have thought concentrating them would be common sense.

Seemed reasonable to me and after reading several posts in different places stating that many BoB British pilots were lacking in skills, I came to take it as fact. I'm not bashing British pilots, merely passing on what I have read in this forum. Everyone in WW2 had periods where they were putting pilots in combat that weren't ready.
 
The Air Ministry (not the RAF) stayed with the battery of 4 x .303" (in the teeth of opposition by Leigh-Mallory) because it was felt that, in a deflection shot (at which, in general, pilots were not very good,) the four guns had a better chance of disabling the enemy pilot, who had little, or no armour at his side, than two slower-firing .5". It had also been found that the .5" was no better at penetration of German armour, in astern shots, which didn't help. And, I'm sorry, Pinsog, but RAF pilots were not "relatively untrained"; "aiming-off" "deflection shooting" call it what you will, takes a certain skill, which not everyone can master, and the likes of Tuck, Johnson, Bader, etc., used to go duck-shooting to hone their skills, something that was not always available to the ordinary pilot.

This is true. There is a difference between being "untrained" and being a bad shot!
Air to air gunnery at the sort of speeds aircraft were flying at by the late 1930s using unsophisticated gun sights (iron rings in some cases) was a difficult art to master. The RAF discovered from early gun camera footage that its pilots were not at all good at estimating range, let alone "angle off". Even firing with little or no deflection (the system that Bader incidentally considered the best, whether he went duck hunting or not) is fairly pointless with machine guns at a range of 1500 yards which was the range that some BoB era pilots were shown to be shooting from.
Cheers
Steve
 
Pinsong, I don't know exactly why the RAF continued using the Browning 303 for so long other than that it still must have been useful. I assume that more and more of the RAF's fighter ammunition was expended against ground targets rather than against air targets as the war progressed. You are right a lot of the Battle of Britain pilots were very inexperienced for the reasons you gave.
 
When the armament of the aircrafts that participated to BoB was decided, however, RAF can't predict to have to rely on a mass of relatively trained/untrained pilots, and when BoB was over, RAF had no more to rely on pilot with litte training, so, as a reason, it doesn't seems so good.
 
It really is astounding the strange stuff, at times, which is written on this subject (how, on earth, could you fit the non-existent Aden 30mm into a Spitfire wing?)
You absolutely couldn't. Don't worry about it.

the RAF did not go for a spread pattern, in fact I have a copy of the harmonisation diagram, for the Vc (which would also have held good for the VII, VIII, IXc, and XIVc until war's end,) which was to be set up at a range of 50 yards, and concentrated the aim of all guns, camera, and gunsight at 250 yards
The RAF changed policy on their harmonisation process several times throughout the war. From early 1940 until mid 1942 the RAF standardized on the 'concentrated pattern'. After which they switched to the 'spread pattern'. As far as I can tell this was used until the end of the war.

When the gyro gunsight appeared in 1944, it changed things completely, since it virtually guaranteed that pilots would hit what they were aiming at, and that was when the Air Ministry finally allowed usage of the .5".
I think there is a lot to this. Although I don't have a specific source for it - reading through Mk.IId Gyro Gunsight manuals indicates that the sight was, of course, calibrated for 20-mm Hispano fire. The .5-inch Browning round roughly corresponds to the same trajectory at the ranges required, whereas the .303-inch Browning is way off. The method for using the Mk.IId sight with .303 Brownings only is very awkward and the whole process is greatly simplified by using the .5-inch Browning as the secondary weapon.
 
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I only recently read that they didnt concentrate all of there weapons into a small area, which was a huge suprise to me. I would have thought concentrating them would be common sense.

Define "small area"?
The standard pattern for a Spitfire had all eight guns hitting an area (or two areas) going from about 1/2 way between the engine and fuselage on one side of an HE 111 at 200 yds to the same point on the other side with a gap in the middle so each "group" much pretty much centered on the wing root. at 300yds they had sort of an overlapped sideways figure 8 only a couple of feet wider than the He 111 fuselage. At 350 yds (the cross over point) all eight guns would have a 75% circle all centered on the He 111 fuselage and no bigger than the fuselage diameter. As has been said, during the BoB the cross over was shifted to 250yds and the 75% circle would have been correspondingly smaller.

How much smaller do you want the pattern to be?
 
Pinsong, I don't know exactly why the RAF continued using the Browning 303 for so long other than that it still must have been useful. I assume that more and more of the RAF's fighter ammunition was expended against ground targets rather than against air targets as the war progressed. You are right a lot of the Battle of Britain pilots were very inexperienced for the reasons you gave.

Same reason we went to war with P39, P40, Brewster Buffalo fighters and Devastator torpedo planes, as Donald Rumsfeld so eloquently put it "you don't go to war with what you want, you go to war with what you have at the time"

The British had no Browning 50's on hand, nor 20mm cannon. What they had was a bunch of Browning 303's and enough ammo to supply them, so that is what they used.
 
Define "small area"?
The standard pattern for a Spitfire had all eight guns hitting an area (or two areas) going from about 1/2 way between the engine and fuselage on one side of an HE 111 at 200 yds to the same point on the other side with a gap in the middle so each "group" much pretty much centered on the wing root. at 300yds they had sort of an overlapped sideways figure 8 only a couple of feet wider than the He 111 fuselage. At 350 yds (the cross over point) all eight guns would have a 75% circle all centered on the He 111 fuselage and no bigger than the fuselage diameter. As has been said, during the BoB the cross over was shifted to 250yds and the 75% circle would have been correspondingly smaller.

How much smaller do you want the pattern to be?

I would want all 8 guns impacting at the same point, 150 to 200 yards(not sure how small a point 8 guns can be focused on). Personal preference, other people might want them spraying all over the place. When I bird hunt, with the exception of quail, I always use a full choke on a shotgun. I don't like to lightly spray a bird and hope it brings it down, I like to hit him with everything I have or miss him clean. Again, just my personal choice, most of my friends use a more open choke than I do on a shotgun, so pilots of the time might want a more open pattern, some might like the tight pattern, others might just use whatever is handed to them and not care.
 
If your target is a bomber and ALL your guns will put ALL the bullets they can ( there seems to a dispersion problem with getting a 100% zone from each gun to to be under several feet at several hundred yds) into an area smaller than the bombers fuselage diameter at 300yds good does going tighter do? That is hardly spraying all over the place like some of the earlier patterns. And if you set the cross point too close you will be spraying all over the place if forced to take a long shot (long being 300-400yds)

from another diagram to show British pilots proper aiming points, if a He 111 is doing 250hp and the fighter is just 7 degrees off the tail at 250yds the proper aiming point is just outboard of the 'inside' engine and level with the fuselage. If the pilot aims at the fuselage his bullets will go just under or barely hit the bottom of the outboard engine nacelle with a 1/3 degree dispersion pattern. If the guns have a 1 degree dispersion pattern there will be at least some hits along the wing, outside horizontal stabilzer/elevator and engine nacelle. at 400 yds and a 11 1/4 degree angle the proper aim point is over the inside wing tip.

By the way a full choke puts 70% of it's pellets in a 30in circle at 40 yds or about 1.25 degrees. a 1.25 degree pattern at 300yds is about 19ft.
 
The RAF changed policy on their harmonisation process several times throughout the war. From early 1940 until mid 1942 the RAF standardized on the 'concentrated pattern'. After which they switched to the 'spread pattern'. As far as I can tell this was used until the end of the war.
The information we have is the other way round; the "Dowding spread" was his original approved method for attacking bombers (which were all that were expected before France fell,) but pilots didn't like it, and swiftly changed over when they encountered small fighters.
I think there is a lot to this. Although I don't have a specific source for it - reading through Mk.IId Gyro Gunsight manuals indicates that the sight was, of course, calibrated for 20-mm Hispano fire. The .5-inch Browning round roughly corresponds to the same trajectory at the ranges required, whereas the .303-inch Browning is way off. The method for using the Mk.IId sight with .303 Brownings only is very awkward and the whole process is greatly simplified by using the .5-inch Browning as the secondary weapon.
At 250 yards, there was little difference in the trajectory of the three different rounds (if there had been, the Air Ministry couldn't have justified sticking with the .303".) Also, the harmonisation chart set the angles of all of the guns so that they met at 250 yards, which negates any differences (if the pilot gets his range right.)
Sorry, Pinsog, but you didn't make it plain that your "untrained" remark concerned only the Battle of Britain (which is true); I was referring to the whole spread of the war.
The problem with your shotgun analogy is that you (presumably) fire from a standing position; try it while running at full pelt alongside the bird, and see the difficulty of aircraft pilots who had to aim a moving object at another moving object, while allowing for "angle-off."
 
The information we have is the other way round; the "Dowding spread" was his original approved method for attacking bombers (which were all that were expected before France fell,) but pilots didn't like it, and swiftly changed over when they encountered small fighters.
Basically correct, but the reason was the inverse. According to representatives of the BAFF (Wing Commander C. Walter), their pilots were supportive of a slightly spread-out pattern in fighter vs. fighter combats - but for destroying bombers the highest density possible was preferred.

Now, don't confuse the Horizontal Pattern ('Dowding Spread') with the Spread Pattern. The latter was different pattern and adopted mid 1942, replacing the Concentrated Pattern ('Point Harmonisation').

At 250 yards, there was little difference in the trajectory of the three different rounds (if there had been, the Air Ministry couldn't have justified sticking with the .303".) Also, the harmonisation chart set the angles of all of the guns so that they met at 250 yards, which negates any differences (if the pilot gets his range right.)

Trajectory wouldn't be the problem, time of flight would.
EDIT: Also, that's the beauty of that Gyro Gunsight. Those 400-600 yard shots that were pointless with the standard gunsight are now possible. And at those ranges the 250 yard harmonisation of .303 and 20mm guns are quite a ways off.
 
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Can you tell me where the references to Spread Pattern come from, please? In 30 years of looking through records, I've never seen mention of it, and what's the BAFF?

Shortround referenced the Spread Pattern here: Flying Guns World War II
The Diagram can be found on page 93 of Tony Williams and Emmanual Gustin's book "flying Guns World War II.

My own references come from documents from the London PRO. I've been writing an article up on RAF WWII harmonisation patterns for a long time now, someday I'll light a fire under it and get it done - hopefully.

BAFF: British Air Forces in France - Wikipedia, the free encyclopedia
 
Curiously, having to face the same enemy, the Soviets came to opposite conclusions than the British, and decided then, at least for cowling mountings, a single heavy MG was better than two light MGs for about the same weight. Both the Yak-1 than the MIG-3 had two 7.62 mm ShKAS MGs replaced with one 12.7 mm UBS (so the first having one UBS and one cannon, the second two UBS) after the first months of war.
 
Curiously, having to face the same enemy, the Soviets came to opposite conclusions than the British, and decided then, at least for cowling mountings, a single heavy MG was better than two light MGs for about the same weight. Both the Yak-1 than the MIG-3 had two 7.62 mm ShKAS MGs replaced with one 12.7 mm UBS (so the first having one UBS and one cannon, the second two UBS) after the first months of war.

The US M2 0.5 in had a performance superior to the British 0.5 in Vickers and inferior to the Soviet 12.7 mm UB and UBS.
 

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