P-40 vs. ME-109

[renrich]

riacrato, thanks for your calculations. Don't worry about converting meters to yards as they are so similar. That is a big difference, almost 15 feet between the strike of the 50 cals and 20mms. It could easily mean a hit with one and a miss with the other.

 

[riacrato]

Well there is a slight difference at that range, 400 yards is about 366 m.

But anyways while there is certainly a difference in point of impact (~4.7m), let's be realistic:

1- at that range you would have to lead the target by about 82 m with a 50 cal, as opposed to 86.7m for the hispano. could you tell the lead difference of 82 vs 86.7 m? So a fighter with 6x50cal would have to lead about 5.7 % less than a fighter armed with 4x Hispano at that extreme range. I suggest someone who can pull off the former can likely pull off the latter.

2- is this a realistic scenario: Full deflection at 400m vs a fast aircraft (at the upper limit of typical dogfight speeds, if not beyond)?



If anything that shows that mixed armaments of cannons and mgs are less optimal when it comes to dogfighting, well known. Still at typical deflection shot scenarios I think the differences between the two guns are minimal.

EDIT: Forget what I wrote, my calculations would only be valid if the attacker is flying at 0 km/h. for an aircraft flying at x km/h the lead for both aircraft would be smaller and the difference between 50cal and Hispano slightly larger. I am too lazy at the moment to try to calculate the values again

 

[Vincenzo]

riarcrato what's difference for a 200 meters range?

 

[Demetrious]

For the purposes of WW2, it depends on the rounds used. HE rounds explode on impact so armor penetration is not really their intended purpose. AP 20mm was shown to be more consistent and more effective up to 400 yards.

Excellent data, both on this and everything else you've posted in this thread. I'm bookmarking your posts for future reference.

Obviously, armor-piercing 20mm rounds will outperform .50 cal against armor (I must admit I'm surprised that ball 20mm was inferior to .50 cal, but considering the blunt tips that makes sense.) However, as I understand it, most all 20mm shells employed in WWII were of the HE variety for it's obvious destructive power.

This information changes the dynamics of these two weapons considerably- HE rounds obviously have the ability to blow entire important pieces of the fuselage off completely, but the rather better armor penetration of the .50 cal, plus the greater pattern density (more guns throwing more bullets) means that .50 cals had a better chance of putting a round into something important and protected- the engine, or preferably the pilot.

That's my take on it, at any rate.

I am not trying to prove that the 20mm was better or equal to the .50 in a purely theoretical case. I am trying to prove that at normal air combat ranges the .50 didn't have enough of an advantage to get all worked up about. Unpleasant as that may be for some .50 cal fans.

Then in that case your own argument is purely semantic as well.

"Normal combat ranges," for most pilots, consisted of saddling up on a bandit's tail at 100 yards or less, with no deflection, since most pilots were crappy shots (given the difficulty of aerial gunnery.) At 100 yards or less, you could easily down your enemy with rifle-caliber machine guns, much less .50 cals or cannons. (The Germans, naturally, facing planes like the Thunderbolt with aircraft that simply didn't have the room to mount more then two MGs in the cowling were in a different situation, but we're talking Allied armaments.)

This also negates arguments about "duration of fire," since running out of ammo hosing bullets at ranges the pilot should know he hasn't the skill to hit at is a matter of pilot discipline. Generous ammo supplies matter most in the context of difficult deflection shots at 200 or 300 yards.

 

[riacrato]

riarcrato what's difference for a 200 meters range?

I calculate ~1.57m. (39.12m for Hispano, 37.55m for 50 cal.).

I would mention though this is all based on that chart provided by bill which says "estimated data". I don't know how good it really is.

 

[riacrato]

riarcrato what's difference for a 200 meters range?

All else being equal (EA at 563.3 km/h, 90 degree deflection) I calculate ~1.57m at 200m. (lead is 39.12m for Hispano, 37.55m for 50 cal.).

I would mention though this is all based on that chart provided by bill which says "estimated data". I don't know how good it really is.


EDIT: Forget what I wrote, my calculations would only be valid if the attacker is flying at 0 km/h. for an aircraft flying at x km/h the lead for both aircraft would be smaller and the difference between 50cal and Hispano slightly larger. I am too lazy at the moment to try to calculate the values again

 

[billswagger]

Obviously, armor-piercing 20mm rounds will outperform .50 cal against armor (I must admit I'm surprised that ball 20mm was inferior to .50 cal, but considering the blunt tips that makes sense.) However, as I understand it, most all 20mm shells employed in WWII were of the HE variety for it's obvious destructive power.

The belting of the ammo was actually a mixture of a variety of ammo.

I don't have exact ratios, but typical Spitfire load outs had lower HE ratios than German fighters.
Don't quote me, but its something like 4 of every 10 rounds mixed with ball and tracer rounds. I think Germans used 7 of 10 HE rounds.

Its just depends on the given roll of the aircraft, Ground attack missions would carry more AP load outs, while air to air was HE.

It is rare to see aircraft that use entire beltings of one specific ammunition type, although there are a few cases i can site.

When you have a multi gun platform of 6 or 8 guns that all have the same exact trajectory and ballistics properties then you only need put tracer rounds in a couple of the guns.

P-47 pilots would sometimes load 6 guns with 100% AP or API, and have two guns 100 percent incendiary. The 6 guns would work well on hitting vital aircraft parts at long range while the "I" rounds acted as a steady bead of tracers and ignited flammable materials.

http://www.wwiiaircraftperformance.org/p-47/er/56-gabreski-29jan44.jpg
http://www.wwiiaircraftperformance.org/p-47/er/56-gabreski-30jan44.jpg

Bill

 

[Vincenzo]

The Putnam Aeronautical Review - Google Books

in the Kuerfurst page there is the RAE report take on base of that article.

as all enemy report i want just noted that the plane was crashed, was not absent to trouble, the pilot and ground crew were not trained on this

 

[Vincenzo]

T

http://www.wwiiaircraftperformance.org/p-47/er/56-gabreski-29jan44.jpg


Bill

as i understand only AP in six guns and only API in two (idk if 50 has HEI)

 

[billswagger]

as i understand only AP in six guns and only API in two (idk if 50 has HEI)

I'm not sure the US Army ever used HE 50 caliber in WW2 combat.

The combat report is referring to Incendiary Tracer rounds.

API is a different kind of ammo. There is no tracer element. It emits a flash on impact which lets the pilot know his shots are hitting, and was later discovered could be used to ignite fires.

APIT is the same roundf with the added tracer element.

In the report, he makes note of this.

"I saw no white flashes.........." ..."but i did observe glycol pouring out of the engines"


There are a dozen more reports that show the range of the ammo. What's interesting about the other example broaches another question that should be looked into.

"The 109s had the same white tail and wing markings as the Mustang. As a result, fire was withheld til I closed to 250 yards., when black crosses could be plainly seen......"






Bill

 

[NZTyphoon]

There are a dozen more reports that show the range of the ammo. What's interesting about the other example broaches another question that should be looked into.

"The 109s had the same white tail and wing markings as the Mustang. As a result, fire was withheld til I closed to 250 yards., when black crosses could be plainly seen......"

Bill

I doubt if the Germans would have gone to the trouble of marking 109s to look like Mustangs; for one it would have confused German pilots in the heat of combat and increased the risk of " friendly fire" ; this would have been rather more risky than any potential confusion it may have engendered in enemy pilots.
Secondly, there were Luftwaffe units using white rudders and wingtips at the time and these could easily have been mistaken for Mustang markings - the report doesn't state the range at which the 109s were first sighted, and it states that the Gabreski and Lt Klibbe closed from dead astern - from such an angle even a flash of white could be mistaken for the Mustang markings.

 

[billswagger]

I doubt if the Germans would have gone to the trouble of marking 109s to look like Mustangs; for one it would have confused German pilots in the heat of combat and increased the risk of " friendly fire" ; this would have been rather more risky than any potential confusion it may have engendered in enemy pilots.
Secondly, there were Luftwaffe units using white rudders and wingtips at the time and these could easily have been mistaken for Mustang markings - the report doesn't state the range at which the 109s were first sighted, and it states that the Gabreski and Lt Klibbe closed from dead astern - from such an angle even a flash of white could be mistaken for the Mustang markings.

From what i've seen it was probably not the intention of the Luftwaffe to look like Mustangs however the vertical surfaces of the tail, including the rudder were sometimes painted white. Also there is a stripe on the tail section used to identify different squadrons, flights, or elements. Usually this was yellow, sometimes it was white.

If lining up to bounce an aircraft from 5000ft above these markings could be mistaken for Mustangs.

In Gabreski's other descriptions he shoots from distances over 500 yards, but these aircraft also happen to be the larger Bf110 and Me210, perhaps easier to identify and also hit from longer ranges. In other accounts he does describe hitting smaller aircraft from similar distances using similar ammo load.

I just raises the point that sometimes hitting the target is not only a matter of range, but also being able to correctly identify the target before you open up on it.

Bill

 

[Milosh]

From what i've seen it was probably not the intention of the Luftwaffe to look like Mustangs however the vertical surfaces of the tail, including the rudder were sometimes painted white. Also there is a stripe on the tail section used to identify different squadrons, flights, or elements. Usually this was yellow, sometimes it was white.

Bill

The stripes were not unit markings. The P-47 and P-51 had a stripe, white or yellow, on each wing, each stab/elevator and fin/rudder for ID purposes to distinguish them from 190s and 109s.

 

[billswagger]

The stripes were not unit markings. The P-47 and P-51 had a stripe, white or yellow, on each wing, each stab/elevator and fin/rudder for ID purposes to distinguish them from 190s and 109s.

agreed.

I think perhaps the white tail used on P-47s as well as Mustangs and P-40s was confused with the vertical tail surfaces of the 109s as well as a white stripe on the tail section.

Actually the white rudder was a way to distinguish flight leaders of the 109.

I'm not as familiar with markings other than the obvious allied stripes used on the wings and underbelly.



Bill

 

[billswagger]

Kurfrst - U.S.A.A.F. Material Command - Pilot's Comments on ME 109G[-6/trop], AAF No. EB-102

this is a P-40 pilots assessment of a 109G. Although no specific performance comparisons are made, he makes several remarks that indicate the plane had a poorer turning radius due to heavy elevator forces at 400kph above which these forces only increased.


Bill