Sorry.... Comparing Darwin to Guadalcanal.
Japanese Zero vs Spitfire vs FW 190
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Sorry.... Comparing Darwin to Guadalcanal.
Shortround6
Major General
The .50 cal M1 ball lost about 300fps by the time it reached 300yds at sea level, this was with just under .40 secs time of flight. At higher altitudes the time of flight is less and the velocity loss is less. I don't have the tables of fire for the .303 at hand but the US M1 Ball (174 grain boat-tail at 2650fps mv) had a time of flight of 0.39 seconds to 300yds.
The .50 cal has a tremendous advantage at long range, at short ranges (like 300 yds) not so much. It is cumulative. I don't worry to much about hundreds of a second in flight time, it is tenths of seconds that start to amount to something.
The M2 Ball and AP rounds show a rather better advantage since they start out about 15% faster with times of flight that reflect that.
They also hit a lot harder. Like over 30% more kinetic energy than the M 1 Ball or M1 AP for doing things like bursting that water drum.
michael rauls
Tech Sergeant
- 1,679
- Jul 15, 2016
For whatever it's worth Wildcats/Martlets accounted for 50 some( I believe it's 52) German aircraft. How many constitutes regular fighting im not sure but 50 some odd victories and not sure how many damaged seems like more than than a one of kinda thing.
Glider
Captain
It's also worth remembering that Seafires had the Hispano V which were a noticeable improvement on the Hispano II being both lighter and faster firing, so the effect would have been increased.
Shortround6
Major General
The naval P-36 is pretty much a non-starter.
see. http://www.wwiiaircraftperformance.org/P-36/P-36_Operation_and_Flight_Instruction.pdf
Take off run for a P-36C at 5800lbs was 600ft zero wind and using 30 degrees of flap.
Take off run for an F4F-3 at 7543lbs was 690ft zero wind.
Take off run for an F4F-3a at 7320lbs was 650ft zero wind.
Take off run for an F4F-4 at 7973lbs was 710ft zero wind.
Take off run for an P-40E at 8289lbs was 1070ft zero wind.
Now to get a P-36C to weigh 5800lbs you have to start leaving things out as the gross weight was 5838lbs and the max safe flying weight was 5840lbs, anything over that and the plane had restrictions.
This weight is with 105US gallons of fuel, a 66lb radio, one, 50 cal with 200 round and three .30 cal guns with 500rpg.
Filling the fuel tank behind the pilot added 348lbs, extra oil to last as long as the fuel was another 26lbs.
The F4F3s were carrying 42 gallons more fuel and enough oil. They also had armor, self-sealing tanks, 129lbs worth of radio/communications gear, survival gear, and so on.
P-36s also had trouble with wing skin buckling over the landing gear when landing on land. Slamming them onto carrier decks without beefing up the structure probably wasn't going to work well.
IF you can get the USN to forego armor and self sealing tanks and IF you can get them to agree to a lower fuel capacity and IF you can limit the guns to the P-36C armament or six .30 cal guns and no .50s and IF you can get by with less radio gear and no life raft and...............................
Then maybe you can get a Naval P-36 but it you do, what have you really got?
BTW changing to the engine used in the F4F3A will add 92 pounds and the 2 stage engine will add 192 pounds of dry engine weight.
A P-40 no letter weighed 673lbs more than the P-36C empty and that includes 292 lbs of radiator and coolant.
If you add much weight at all the structure will have to be beefed up (which adds weight) to meet the usual American strength requirements. The early P-40 wing gained over 100lbs from the Hawk/P-36 wing.
How heavy does the P-36 get before it can no longer safely operated from the carrier decks?
see. http://www.wwiiaircraftperformance.org/P-36/P-36_Operation_and_Flight_Instruction.pdf
Take off run for a P-36C at 5800lbs was 600ft zero wind and using 30 degrees of flap.
Take off run for an F4F-3 at 7543lbs was 690ft zero wind.
Take off run for an F4F-3a at 7320lbs was 650ft zero wind.
Take off run for an F4F-4 at 7973lbs was 710ft zero wind.
Take off run for an P-40E at 8289lbs was 1070ft zero wind.
Now to get a P-36C to weigh 5800lbs you have to start leaving things out as the gross weight was 5838lbs and the max safe flying weight was 5840lbs, anything over that and the plane had restrictions.
This weight is with 105US gallons of fuel, a 66lb radio, one, 50 cal with 200 round and three .30 cal guns with 500rpg.
Filling the fuel tank behind the pilot added 348lbs, extra oil to last as long as the fuel was another 26lbs.
The F4F3s were carrying 42 gallons more fuel and enough oil. They also had armor, self-sealing tanks, 129lbs worth of radio/communications gear, survival gear, and so on.
P-36s also had trouble with wing skin buckling over the landing gear when landing on land. Slamming them onto carrier decks without beefing up the structure probably wasn't going to work well.
IF you can get the USN to forego armor and self sealing tanks and IF you can get them to agree to a lower fuel capacity and IF you can limit the guns to the P-36C armament or six .30 cal guns and no .50s and IF you can get by with less radio gear and no life raft and...............................
Then maybe you can get a Naval P-36 but it you do, what have you really got?
BTW changing to the engine used in the F4F3A will add 92 pounds and the 2 stage engine will add 192 pounds of dry engine weight.
A P-40 no letter weighed 673lbs more than the P-36C empty and that includes 292 lbs of radiator and coolant.
If you add much weight at all the structure will have to be beefed up (which adds weight) to meet the usual American strength requirements. The early P-40 wing gained over 100lbs from the Hawk/P-36 wing.
How heavy does the P-36 get before it can no longer safely operated from the carrier decks?
Hello Shortround6,
First of all, the .303 174 grain starts off at about 2475 fps from the muzzle out of a 25 inch barrel. I don't know if the Aircraft ammunition was loaded hotter or if the barrels of the aircraft MG were longer. I don't believe it ever exceeds 2550 fps. The bullets weigh the same but are fatter by just a touch thus probably a lower BC or at least a lower sectional density. As mentioned before, some of them had an air space and an aluminum core at the front, so they might have been longer for a better BC. I don't believe those were available in the mid 1930's when the testing was done.
Also, as I understand it, the US .30 cal M1 (pretty much the same as a M72 Match round) actually had a bit higher muzzle velocity than you are listing here. It was more like 2700 fps or so. The 2640 fps or what is typically listed on the box is velocity at 78 feet instrumental.
- Ivan.
Shortround6
Major General
The MK VII bullet was adopted in 1910. Even with the normal delays between adoption and introduction into service this was the standard round in WW I. It was most certainly available for testing in 1930s.
The MK VIIIz with boat tail was adopted in the very late 30s but may not have seen aircraft use?
The point is that at 300yds or so the difference between the times of flight of the slow/early .50 cal ammo and the British .303 ammo are so small as to be unimportant. At much longer ranges the differences do become much larger and assume greater importance.
The MK VIIIz with boat tail was adopted in the very late 30s but may not have seen aircraft use?
The point is that at 300yds or so the difference between the times of flight of the slow/early .50 cal ammo and the British .303 ammo are so small as to be unimportant. At much longer ranges the differences do become much larger and assume greater importance.
Kevin J
Banned
In the MTO the Seafire IIc / LIIc could intercept then drive off attackers, the Martlet was too slow.
Hello Shortround6,
First of all, you are using a round that has about 200 fps more muzzle velocity (than the .303) as a comparison.
Second, I was comparing retained velocity (between .303 and .50), not time of flight.
Third, if the two projectiles you chose to compare (the .30 and .50) have the same time of flight but the .30 starts off 200 fps faster, that means that its final velocity will be much slower because its AVERAGE velocity is the same.
Since you are using a .30 cal as an example for ballistics and the .303 is considerably slower, there is no way it will retain nearly as much velocity downrange unless something very very strange is happening.
Also, as you just pointed out, the .303 probably wasn't using a boat tail bullet (which I thought it was), so it would be losing velocity even more quickly.
Thus, you are actually proving my point.
- Ivan.
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I have one comment and three questions on the guns.
My comment is that if you were trying to shoot down an enemy bomber with defensive armament, the 12.7mm gun is a much better bet than the .303. Against an enemy fighter with armor, the 12.7mm is again better and more likely to kill the target from a further distance.
My questions:
My comment is that if you were trying to shoot down an enemy bomber with defensive armament, the 12.7mm gun is a much better bet than the .303. Against an enemy fighter with armor, the 12.7mm is again better and more likely to kill the target from a further distance.
My questions:
- What is the firing time for 60 rounds from a Hispano cannon with 60 rounds? 6 -10 seconds?
- What is the firing time for an M2 .50 cal with 450 rounds? 40-50 seconds?
- Both the M2 Browning and the Hispano 20mm were known for serious problems with gun-stoppages / jams in the early years of the war. Which one was worse in that respect?
- Did the motor-cannon / hub mounted 20mm generally speaking (ShVAK or Mg 151 or whatever) have less problems with stoppages? Because this is what I have read anecdotally.
Well, in theory. Have you read about the Seafire in Italy? They lost 70 Seafires from landing accidents alone at Salerno. Not so great.
Glider
Captain
If the HMG was the better weapon against bombers, then why did nearly all the nations switch to the 20mm? Against a fighter a 20mm is going to do far more damage than a 0.50 at any range due to the explosive warhead.
a) 6 seconds from a 60 rd magazine but by the time the USA entered the war the Spit had 120 rds as the norm
b) 35 Seconds
c) By 1942 the 20mm issues had been resolved whereas the 0.50 were still being looked at
Bonus
I don't think so. The 20mm was designed for mounting in the hub and my understanding was that it was far more reliable from the start, the problems began when the gun was moved to the wing. The vast majority of French fighters had them mounted on the centre line.
Ok some followup.
A) I don't think this is correct because apparently a lot of Spit VB in the MTO were still using 60 round drums through the second half of 1942 and well into 1943, so I'm a little bit confused here. Can you clarify?
B) Again, a little confused because I'm showing 600 rpm, which translates to 10 rounds per seconds, so that would be 45 seconds would it not?
C) Also in the med, and in Darwin, stoppages seemed to continue to be a major problem with the Hispano 20mm.
On the Bonus question - I would agree, it seems to be that the hub mounted guns were more reliable, if not perfect.
A) I don't think this is correct because apparently a lot of Spit VB in the MTO were still using 60 round drums through the second half of 1942 and well into 1943, so I'm a little bit confused here. Can you clarify?
B) Again, a little confused because I'm showing 600 rpm, which translates to 10 rounds per seconds, so that would be 45 seconds would it not?
C) Also in the med, and in Darwin, stoppages seemed to continue to be a major problem with the Hispano 20mm.
On the Bonus question - I would agree, it seems to be that the hub mounted guns were more reliable, if not perfect.
Those were Seafires landing on CVEs in extremely light winds. No other Allied naval fighter would have done any better except maybe the Sea Hurricane.
Clayton Magnet
Staff Sergeant
- 868
- Feb 16, 2013
These "Cannon vs. Machine Gun" arguments have been done to death, and always seem to be divided on National lines. The Americans praise the M2 Browning, while everyone else prefers 20mm. I think history is quite clear as to what is the more effective air-to-air armament.
Once aircraft had the lifting capability to effectively wield auto-cannons, they generally did, and still do.
Once aircraft had the lifting capability to effectively wield auto-cannons, they generally did, and still do.
I just don't think it was that simple. I've seen both 20mm cannon and .5 in machine guns fired, and I've shot the latter myself (at ranges) so I do find them impressive, but I'm not stupid - in many respects 20mm cannon were better. But as with anything to do with WW2 aircraft (and most other things) the devil is in the details. One of the questions is how much better. You can pretend it's not an issue but stoppages were a real problem for most wing-mounted guns. So was the limited armament of early cannon, even 120 rounds isn't that much, 60 is a real limitation. So it's a trade-off.
Personally I would not say that 12.7mm machine guns are better or even close to equal to 20mm cannon. Cannon are just better at tearing apart aircraft because they can rip away the skin and structure. Cannon AP rounds also penetrate better.
However, are two 20mm with 60 rounds each better than 6 x .50s? I'm not convinced. It's a tradeoff, like everything in aircraft design. I think maybe the HMGs are better for carrier aircraft four a couple of different reasons. But it's also true that the only reason the US didn't switch over the cannon wholesale was that they couldn't figure out how to make the Hispanos work, didn't have a viable alternative design either, and ultimately figured the HMGs were "good enough."
The debate here though which was started, kind of as a derail, sprang from the claim that .303 machine guns were better / more useful than the 0.5 inch. Which is just not reality during the actual war.
Personally I would not say that 12.7mm machine guns are better or even close to equal to 20mm cannon. Cannon are just better at tearing apart aircraft because they can rip away the skin and structure. Cannon AP rounds also penetrate better.
However, are two 20mm with 60 rounds each better than 6 x .50s? I'm not convinced. It's a tradeoff, like everything in aircraft design. I think maybe the HMGs are better for carrier aircraft four a couple of different reasons. But it's also true that the only reason the US didn't switch over the cannon wholesale was that they couldn't figure out how to make the Hispanos work, didn't have a viable alternative design either, and ultimately figured the HMGs were "good enough."
The debate here though which was started, kind of as a derail, sprang from the claim that .303 machine guns were better / more useful than the 0.5 inch. Which is just not reality during the actual war.
Wildcats / Martlets seemed to operate just fine on CVEs, including very marginal ones and in awful conditions. I never heard of a Naval fighter with that much of a problem as 70 aircraft lost in two days (even if they eventually repaired almost half of them). I understand why they wanted to make a naval fighter out of the Spitfire, it was the best allied fighter in air to air combat for most of the war. But I don't think it was actually suitable for Naval use. Plenty of Brits and Commonwealth pilots seem to agree.
FAA Pilot Hugh Popham's view:
From "Sea Flight: The Wartime Memoirs of a Fleet Air Arm Pilot"
The Hurricane was a good aeroplane, on land, on a deck or in the air. The Spit was adequate on a runway, bad, as it turned out, on a deck, but in the air one of the most exquisite machines ever made by man. It was beautiful to look at with that knife-fine wing-section and the two sheer ellipses of its leading and trailing edges, and with that flowing line from spinner to fin. And it was beautiful to fly, light and quick on the controls, without vices. It was always said that Mitchell's wife designed the lay-out of the cockpit; whether it was true or not, it was a pretty compliment, for it was as neat as a new kitchen. Against its incomparable virtues could be set its silly little undercarriage, which was quite inadequate against the rough and tumble of deck-landing, and the long, long nose which stretched away in front of the pilot ad made him practically blind in the traditional, nose-up, deck-landing attitude. In so far as it had never been designed for a deck, it was unfair to charge the designer with these disadvantages: they were the outcome of a makeshift policy towards Fleet Air Arm aircraft which threw us on to the doubtful mercies of obsolescent R.A.F. machines, hastily modified, or on to the Americans.
FAA pilot Henry "Hank" Adlam's view:
From "On and Off the Flight Deck: Reflections of a Naval Fighter Pilot in World War II"
The Seafire, which was a normal Spitfire with the attachment of a hook for deck-landing, was in reality entirely unsuitable for Carrier operations. The narrow track of the undercarriage, its fragility and that of the whole fuselage made the Seafire unable to cope with the constant stresses of Carrier landings. The big wooden propeller constantly shattered because it had too little deck clearance. The aircraft had a very limited range, no bomb load and, with the extra weigh of the hook, was not all that much faster than the Wildcat and with lesser fire-power. The in-line engine, with the scoop-type coolers under the wings, made a successful 'ditching' in the sea difficult. But also, although a beautiful machine just to fly, it was very difficult to deck-land because of its tendency to 'float' over the wires when the engine was cut. Over the years, in the process of operating from Carriers, the Seafire seriously hurt or killed many pilots. Yet there were a few pilots of above average ability who loved the thing, despite its many faults as a Carrier aircraft.
buffnut453
Captain
It rather depends on the specific timeframe within the war that we're talking about. In the summer of 1940, the .303 was absolutely a better weapon than the 50cal because the latter simply wasn't a workable weapon solution in wing-mounted installations. The significant issues with the 50cal continued until at least the middle of 1942 and, in some cases, through Q3 of that year. I absolutely agree that the 50cal offered considerable advantages during the period late-1942 thru the end of 1943 but after that point I think cannon armament was absolutely ascendant.
Kevin J
Banned
I know. That was a success because they chased away attacking Jabo's.
