British .303 vs 50 Cal M2

[David Fred]

Thanks. Now that I am getting on a bit, I find the time to buy and read these specialist books, and this is a good one, not cheap, and supposedly in "layman's terms" (layman what I can't imagine).

From the same book, this photo from a WW2 secret diagram of a Mk1 Spitfire hit probability against an He-111.

The dotted lines represent that 100% of rounds landed within that area, the solid lines, 70%..

Top to bottom, 100, 200, 300, and 400 yards, with the guns harmonized at 350 yards.

Also, elsewhere in the book they mention that dispersion increased greatly in a hard turning, high G fight, because the Spitfire thin wing was subject to torsional effects, which had less effect on the inboard Guns, but quite a lot on the outboard guns.

In fact, as you read below, from "Fighter Aircraft Performance Of WW2: A Comparative Guide", by Erik Pilawskii.

It speaks to why so many pilots who had flown both the Hurricane and Spitfire praise the Hurricane as a "more stable gun platform."

 

[David Fred]

I am not understanding some of the tables.
Rate of fire isn't making sense as labeled. rate of fire for the number of guns over how many seconds?
Energy at impact at what range or impact velocity?
Energy at impact for how many projectiles?

BTW the velocity for the .303 is incorrect, Velocity was between 2400 and 2500fps for most service rounds used in WW II.

Rate of fire in combat bursts, primary source Wing Commander H.R. Allen, DFC, from his book, "Who won the Battle of Britain", where he cites studies done by the RAE. The rest of the data is from the same source, but extrapolated, because as Allen points out, the studies were done early, when comparing 6 .303 Guns with 4 M2's.

If you want more about methodology, but Allen's book. I can't photocopy 6 pages here.

 

[fastmongrel]

I'm sure that most RAF pilots in 1940 were more accurate than your wild disrespectful shooting off of the mouth.

Do some research before posting and you will find that most RAF pilots in Aug/Sept 1940 had very poor shooting skills.

 

[pbehn]

Do some research before posting and you will find that most RAF pilots in Aug/Sept 1940 had very poor shooting skills.

Some threads on this forum are useful.
RAF Pilot Training in WW2
RAF Pilot Training Hours 1940

However it wasn't just RAF pilots in 1940 it was all pilots, the gyro gunsight improved marksmanship in all services that used it.

 

[Zipper730]

From what I remember, the RAF had considered fitting the 0.50 to the bombers, but the arrival of the USAAF prevented that for some reason

 

[MycroftHolmes]

Do some research before posting and you will find that most RAF pilots in Aug/Sept 1940 had very poor shooting skills.

Pbehn has got in first, but the great majority of pilots in all air forces were poor marksmen, for the simple reason that aerial gunnery is very difficult. The difference was that the RAF looked at the performance of its pilots with a cold and objective eye and realised that they weren't doing very well, so they thought about how to improve matters and produced the gyro-gunsight. By contrast, the Luftwaffe/USAAF/USN were rather smug and complacent and simply assumed that all was well. If you believe otherwise, you are implying that British pilots are somehow genetically incapable of good shooting, since the RAF certainly spent considerable time and effort on gunnery, including deflection-shooting.

 

[pbehn]

Pbehn has got in first, but the great majority of pilots in all air forces were poor marksmen, for the simple reason that aerial gunnery is very difficult. The difference was that the RAF looked at the performance of its pilots with a cold and objective eye and realised that they weren't doing very well, so they thought about how to improve matters and produced the gyro-gunsight. By contrast, the Luftwaffe/USAAF/USN were rather smug and complacent and simply assumed that all was well. If you believe otherwise, you are implying that British pilots are somehow genetically incapable of good shooting, since the RAF certainly spent considerable time and effort on gunnery, including deflection-shooting.

The summer of 1940 was a desperate time, pilots were not trained long enough in any skill let alone gunnery which was done in many cases at OTUs. The gyro gun sight was being worked on before the war started with the first version in production in 1941.

 

[Shortround6]

The subject of air to air gunnery (as opposed to the subject of the guns) is a woefully under studied one.
I don't believe that any nations (people) were any better or any worse shots than any other.
What differed was Instruction and Practice. The Quality of both and the Time spent on both. These varied considerably throughout war in just about every Air Force (or every Air Force?). Let alone from air force to air force.

For example For the US you had John Thach, " graduated from the United States Naval Academy in 1927 and spent two years serving in battleships, before becoming a Naval Aviator in early 1930.[2] Thach spent the next decade serving as a test pilot and instructor and establishing a reputation as an expert in aerial gunnery"

another source says that during part of that time he was a gunnery instructor. Please note that he had been flying for 12 years at the time of Midway.

"In the early 1940s, he was placed in command of Fighting Squadron Three (VF-3). There he met a young ensign just out of flight school, Edward O'Hare, later a Medal of Honor recipient. Thach made O'Hare his wingman and taught him everything he knew. At the U.S. Navy fleet gunnery competition at the end of 1940, eight of the 16 VF-3 pilots qualified for the gunnery "E" award ("excellence")"

See: Butch O'Hare and the Thach Weave | U.S. Naval Institute
For an interesting story about Thach and Butch O'Hare.

Unfortunately for the british, it seems to an outsider, that too much of the 30s was spent on NEW theories (no allowance shooting/turrets, aiming fixed guns in multiple directions) ) and not enough on getting the most out of what they had. Gunnery training seems to have been done on once a year (?) camps where the squadrons left their home fields and operated out of the gunnery (or bombing) field/base for one or two weeks. I could be wrong about this but this is hardly the way to reach high standards of proficiency. I would note that Thach was probably an exception to the rule of how the USN was operating/training at the time.

The Boffins can invent all the fancy sights they want (not to disparage the Boffins, better equipment is always useful) but if time is not given to training and practice then the improvements in equipment are never up to what they could be.

 

[Clayton Magnet]

Thanks. I think the cannon was well suited for bomber work, but I like the .50 "hail of lead" against inline engines or the light Japanese aircraft

Then wouldn't 8x 303 be even more effective? far more projectiles in the air, far better percentage for a critical hit.
But simply punching holes was determined to be insufficient. Whether an aircraft was liquid cooled or air cooled largely didn't matter, the best way to destroy either one was to hit it with explosive cannon shells.
There is an interesting love affair with the M2 .50, and its effectiveness is always exaggerated as an air to air weapon. It could certainly BE effective, but history shows that cannons were the way forward.

 

[pbehn]

During the BoB the British had experience of literally hundreds of bullets hitting a bomber without bringing it down. Perhaps there is more psychology. The British were having to bring down bombers over the UK and wanted to do it as quickly as possible, not knowing what will come next. Since the RAF had new bombers on order it would be reasonable to expect the LW did too.

 

[fastmongrel]

The British were having to bring down bombers over the UK

Many in the RAF believed that shooting down Bombers was less important than breaking up the main bomber force and preventing a cohesive force dropping all their bombs on target.

 

[pbehn]

Many in the RAF believed that shooting down Bombers was less important than breaking up the main bomber force and preventing a cohesive force dropping all their bombs on target.

Well it is a valid discussion, if their target is your airfield or plane factory stopping a successful attack is probably more important than the number of bombers shot down, a different calculation when a city is being attacked.

 

[fastmongrel]

Well it is a valid discussion, if their target is your airfield or plane factory stopping a successful attack is probably more important than the number of bombers shot down, a different calculation when a city is being attacked.

The early attacks were targeted even if it was a large area like London Docks. I think targetting cities came later with the Night Blitz.

 

[pbehn]

The early attacks were targeted even if it was a large area like London Docks. I think targetting cities came later with the Night Blitz.

There were many facets to the discussion, for example Dowding was frustrated by pilots mobbing one damaged bomber eventually bringing it down. He considered it much better to damage many than down a few. Park and Dowdings policy of meeting every attack with something meant there were very few "free hits" with bombers being completely undisturbed, when they did they could cause serious damage.

 

[Greyman]

By contrast, the Luftwaffe/USAAF/USN were rather smug and complacent and simply assumed that all was well.

I think that's a mischaracterization of the other nations' efforts. They were on the case - the other countries were just out-boffin'd by the Brits.

And props are due to the French who had the first two successful gyro gunsights (Alkan-Genin type and LMS type). They took two people in a Potez 630 to operate - but hell, they got about 30% hits on Heinkel-sized targets over 500m away.

There was also a Schneider-Fieux sight the French had in the works that turned out to be on a similar path as the British Gyro sight in October 1939.

Then wouldn't 8x 303 be even more effective? far more projectiles in the air, far better percentage for a critical hit.

In Burma/India the Hurricane IIb squadrons were even removing four of their 12 guns because they found eight .303 guns sufficient and the little extra performance would be worth it.

 

[pinsog]

In Burma/India the Hurricane IIb squadrons were even removing four of their 12 guns because they found eight .303 guns sufficient and the little extra performance would be worth it.

They were removing guns because they were desperate, the Hurricane was inferior to the Japanese opposition

There were many facets to the discussion, for example Dowding was frustrated by pilots mobbing one damaged bomber eventually bringing it down. He considered it much better to damage many than down a few.

I can't imagine this line of thinking. If you have 10 rats on your doorstep and you just run them off with a broom, tomorrow there will be 10 rats back on your doorstep. If you obliterate 1 rat with a 12 gauge shotgun, tomorrow there will only be 9 rats. Same thing applies to bombers attacking your cities.

Then wouldn't 8x 303 be even more effective? far more projectiles in the air, far better percentage for a critical hit.
But simply punching holes was determined to be insufficient. Whether an aircraft was liquid cooled or air cooled largely didn't matter, the best way to destroy either one was to hit it with explosive cannon shells.
There is an interesting love affair with the M2 .50, and its effectiveness is always exaggerated as an air to air weapon. It could certainly BE effective, but history shows that cannons were the way forward

There is not that much space inside a WW2 combat aircraft that is simply open space for bullets to pass harmlessly through aside from maybe the outer wings. The wings held weapons, ammo, fuel, control cables and linkage aside from structural wing spars and such. The body obviously held the engine, pilot, fuel, control linkage etc. If you aim to hit center mass where the wing and body join, you should be hitting the pilot, fuel tanks etc.

Not sure what country you live in, but have you ever seen or held a 30-06 and a 50 BMG together? There is a huge difference in what a 150 grain and a 750 grain bullet look like and what damage they will do. Self sealing fuel tanks were generally very effective against rifle caliber fire while a single 50 could actually burst the tank at the seems. Many pilots were wounded by rifle caliber machine-gun fire, flew home, recovered and fought again since a 150 grain 30 caliber bullet would lose so much energy after passing through some aircraft structure. A 50 on the other hand, is a whole different ballgame. Unless you have true armor plate behind you, a 50 could pass through some significant structure, tumble sideways and still have plenty of power left to gut you like a fish. A 50 also has the mass/power to damage/sever lager aircraft structure like wing spars.

Some of you gentlemen who have served in the armed forces and used the 50 on targets such as old trucks etc should chime in with what you have seen it do.

 

[Shortround6]

Sights were going through a rapid evolution at this time also.

Some countries were using an "optical sight" sometimes called telescopic.

These actually offered little or no magnification.
What they did do was place the aiming mark and target in the same focal plane (they would appear to be the same distance from the pilots eye making it easier to focus). They gave bit more leeway to where the pilots eye could actually be without affecting the point of impact like the ring and bead. And the pilot now had to only line up two things. The aiming mark and the target. With the ring and bead he had to line up the target, the front part of the ring and bead and the rear part.
Please note there is NOTHING to help the pilot estimate range with with ether set up or to assist in any way with defection shooting except the pilots experience.

More in next post

 

[Clayton Magnet]

Some of you gentlemen who have served in the armed forces and used the 50 on targets such as old trucks etc should chime in with what you have seen it do.

Now compare the effect of an explosive 20mm projectile.
This was caused by 3 hits from a Oerlikon, and the aircraft was scrapped as a result.

 

[pbehn]

I can't imagine this line of thinking. If you have 10 rats on your doorstep and you just run them off with a broom, tomorrow there will be 10 rats back on your doorstep. If you obliterate 1 rat with a 12 gauge shotgun, tomorrow there will only be 9 rats. Same thing applies to bombers attacking your cities.
.

This was provoked by as many as seven pilots making joint claims for one enemy aircraft. There is a sound logic to it. If an aircraft is damaged over London, it still has a long way to fly back and land. Examination of post war records showed a lot of bombers landed but were effectively written off , ditched in the channel or made a crash landing. It was in a way a side effect of the "Big Wing" when you have a wing of 50 aircraft all together in a small area they completely outnumber the attacking bombers even if the total number of bombers was in the hundreds.

 

[pinsog]

Impressive damage from 3 rounds. I would never argue round for round damage with 20mm vs 50. I would like to point out that this is a Spitfire (not reputed to be the toughest fighter of the war) and yet it still flew home, pilot landed safely, pilot lived to fight another day and plane was probably scrapped because they had more available not because it wasn't repairable. It also proves the point that, like hunting, where you hit them is many times more important than what you hit them with (within reason). If that group had been 12 feet farther forward, that Spitfire wouldn't have made it home.