Author Topic: 303's .... (Read 4052 times)

Tony Williams · « **Reply #30 on:** October 19, 2006, 07:45:08 PM »

Quote

Originally posted by Sombra
I have a question for Tony, or whoever knows.

Reading the article about BoB, it says RAF selected 225 meters (250 yards?) after trying 360. Does it mean it was the adviced convergence, mandatory convergence...? Did the pilot have a say in the convergence for his plane? I ask mainly because I would like to know if it would be historically "accurate" to fly BoB planes with a custom convergence. Thx.

Actually the RAF tried several different convergence patterns (and the FAA had their own). This wasn't up to the pilots, each squadron was told what to use and the results compared. I've read a letter from Dowding in which he complained that the Luftwaffe was failing to cooperate with this research because they kept crashing their planes into the sea where they couldn't be examined - I hadn't realised that Stuffy had a sense of humour!

I should point out that the original setting of 400 yards was not decided on in the expectation that that would be the killing distance. What they wanted at first was a spread of fire across the target, preferably covering both engines as well as the fuselage of a twin-engined bomber. They expected shooting to take place within the 200-400 yard zone. With battle experience, they realised that effective shooting took place at a shorter distance, and that the fire of the .303s had to be more concentrated to be effective, so they dropped to 250 yards as standard. When the Hispanos were first issued the RAF wanted them zeroed at 200 yards, but the Spitfire's gunbays weren't wide enough to angle them in that much, so they had to settle for 300.

It is worth stressing a point made in my article: that the planes on both sides got tougher during the summer of 1940, with armour apparently being added in the field as a result of battle experience. So the effectiveness of the .303s - quite good in the Battle of France - was significantly less by the end of the BoB.

Tony Williams: Military gun and ammunition website and discussion forum

Waffle · « **Reply #31 on:** October 19, 2006, 08:15:03 PM »

Quote

Originally posted by Krusty

4) bombers in real life didn't "cruise" at full throttle, as they do in Aces High. AH has bomber speeds WAY too high, because nobody cruises.

Neither did the fighters......

Stoney74 · « **Reply #32 on:** October 19, 2006, 08:26:42 PM »

Quote

Originally posted by Waffle BAS
Neither did the fighters......

I think you're in the wrong thread, or is this an analogy to the whole "real world" vs. Aces High portion of this one?

Waffle · « **Reply #33 on:** October 19, 2006, 08:40:40 PM »

no - I know what thread I'm in - just making a counterpoint about Krustys point earlier in this thread.

Oldman731 · « **Reply #34 on:** October 19, 2006, 08:42:22 PM »

Quote

Originally posted by Benny Moore
As I've stated repeatedly in this thread, I've never seen an aircraft structurally destroyed at all, except for Japanese aircraft and aircraft carrying explosives.

There are some few photographs of 8th AF bombers suffering fatal structural damage - one famous one of a B17 with a wing loss caused by 262 fire comes to mind. Otherwise I agree with you. Mathematics to the contrary, crew hits and engine/fuel hits seem to have been the cause of most 8th AF losses.

- oldman

Stoney74 · « **Reply #35 on:** October 19, 2006, 09:20:44 PM »

Quote

Originally posted by Waffle BAS
no - I know what thread I'm in - just making a counterpoint about Krustys point earlier in this thread.

Sorry, I thought I remembered that quote from another thread...

gripen · « **Reply #36 on:** October 19, 2006, 11:22:05 PM »

Quote

Originally posted by Oldman731
There are some few photographs of 8th AF bombers suffering fatal structural damage - one famous one of a B17 with a wing loss caused by 262 fire comes to mind. Otherwise I agree with you. Mathematics to the contrary, crew hits and engine/fuel hits seem to have been the cause of most 8th AF losses.

Seems that also Luftwaffe believed that engine and fuel line hits were most effective because these were located around the Nacelles (Butch2k's quote above).

gripen

Benny Moore · « **Reply #37 on:** October 20, 2006, 01:20:02 AM »

Yes, but even then, in the video which no one but me seems to have bothered to watch, several of the bombers take several cannon rounds directly in the engine nacelle without stopping the engine (or, I might add, causing any visible damage). Watch the movie, people! Stop talking about how good cannon damage was and watch the stupid film!
http://www.youtube.com/watch?v=HjlN49szFOc
If that's too big for you, then here's a tiny taste. Copy and paste this one.
http://guncam2002.tripod.com/6.avi

HoHun · « **Reply #38 on:** October 20, 2006, 02:21:26 AM »

Hi Benny,

>For everyone to insist that the cannon damage is correct without actually watching a few hours (or even half an hour) of real footage is simply intellectual dishonesty.

There are accepted standards of historical research, and you're invited to prepare an evaluation of gun camera films that actually means anything.

The Luftwaffe figures for how many shells are required to kill aerial targets were actually prepared from gun camera films, complete with knowledge which type of ammunition was used, which belting arrangement was used, and how much ammunition was actually expended.

If you claim to know better than they did just from watching a few hours of footage, that's the same as claiming you can tell that US aircraft won't be affected by the loss of their load-bearing skin just from looking at a cutway diagram: Intellectual stupidity.

Regards,

Henning (HoHun)

HoHun · « **Reply #39 on:** October 20, 2006, 02:27:13 AM »

Hi Tony,

>I've read a letter from Dowding in which he complained that the Luftwaffe was failing to cooperate with this research because they kept crashing their planes into the sea where they couldn't be examined - I hadn't realised that Stuffy had a sense of humour!

In the Big Wing controversy, he once pointed out that he wasn't ready to accept "a Czech squadron's unchecked claims" as proof of the Big Wing's tactical superiority :-)

By the way, I had known about Dowding's spiritualist ideas for a while, but I was surprised when I learned that Conan-Doyle actually wrote a spiritualist propaganda piece using the characters from his "Lost World" series. Seems spiritualism it was fashionable in Britain for a while?

Regards,

Henning (HoHun)

gripen · « **Reply #40 on:** October 20, 2006, 03:11:59 AM »

Quote

Originally posted by HoHun

The Luftwaffe figures for how many shells are required to kill aerial targets were actually prepared from gun camera films, complete with knowledge which type of ammunition was used, which belting arrangement was used, and how much ammunition was actually expended.

Well, nothing in the LW and FAF material I have indicates that structural damage was the main reason for a kill (naturally there will be structural damage when the plane finaly hits the ground). Infact it seems that the effect of the "minen" type projectiles came from the ability to damage something vital equiment (engine, tanks, fuel line etc.) in the large area near the hit - that is also what quote by Butch2k indicates.

If the structural damage had been the main reason for a kill, there would had been lot of gun camera evidence of that. In reality engine damage and fires seem to by far most common reason for the kill - at least according to the gun camera films, including LW training films.

Quote

Originally posted by HoHun

If you claim to know better than they did just from watching a few hours of footage, that's the same as claiming you can tell that US aircraft won't be affected by the loss of their load-bearing skin just from looking at a cutway diagram: Intellectual stupidity.

Generally the WWII planes were stressed for breaking load factors near 10g even in the case of the bombers (assuming that planes were only partially loaded when attacked). Given that normally accelerations over 2-3g are rare for the bombers, it's unlikely that even extensive damage in the skin is fatal. In most cases wing spars were alone stressed for the required loading while function of the skin was to ad torsional stiffness.

gripen

Benny Moore · « **Reply #41 on:** October 20, 2006, 03:39:04 AM »

See Rules #4, #5

Angus · « **Reply #42 on:** October 20, 2006, 04:03:50 AM »

Hehe, Dowding was a spiritualist indeed. After the war I heard he had been talking of all the dead pilots around him.
Anyway, to the subject. There is more than just guncam. There are stills and there are reports. Both are available in more quantity.
It was mentioned above that often the crew of bombers were being killed.
I have a decent reel of LW interceptions, and I remember a B17 or a B24 being shot up from behind without any return fire.
Then here is a little statement:
Nov 25th 1942, N-Africa, SQN Leader Anthony Bartley
"In the late afternoon, I spotted a formation of Ju 87's, called Mac to act as top cover and led my section to attack them. The Ju 87's dived for the ground when they saw us coming and started a frantic evasive action, twisting like corkscrews. I picked one of them who practically turned himself inside out with contortions before I blew his wing off"
I've got tons of this, really.

Tony Williams · « **Reply #43 on:** October 20, 2006, 05:16:48 AM »

There seem to be two separate issues here:

1. How effective were cannon hits in shooting down aircraft.

2. How effective were cannon hits in causing catastrophic structural damage to aircraft.

The first one is really beyond question, in my opinion. The way in which the Germans, the Russians and the Japanese, who all had perfectly good HMGs available, all upgraded to 20mm cannon (and 30+mm where they had heavy bombers to deal with) says it all. The German research into the number of hits required for each type of gun to shoot down aircraft (on average) just provides some statistical underpinning to that.

However, I have no idea what percentage of cannon kills were as a result of structural failure, and frankly I don't think it's that important. It was well known that the vast majority of shootdowns of Allied bombers was due to fire, not structural damage. I would expect that more fighters would suffer structural damage, simply because they were smaller, but I have no data on that.

The British tested the MG 151/20 against the Hispano and concluded that while the German mine shells inflicted more blast damage, the Hisso shells penetrated more deeply and were more likely to inflict structural damage.

Tony Williams: Military gun and ammunition website and discussion forum

Charge · « **Reply #44 on:** October 20, 2006, 05:42:27 AM »

"On the topic of the oh-so-vital load-bearing skin, I've seen enough pictures of aircraft with multiple (three or more) gaping holes in their stressed skin from twenty and thirty millimeter cannon fire to believe that three to six rounds could remove a wing or even a stabilizer from the airplanes in question. Here are just a few examples. The last one was a flak hit and I do not know the caliber."

I have seen some pictures too and they tell me pretty much nothing of the ammo used.

Firstly the people who got hit by ground or by aircraft fire could not always be sure what actually hit them. How could they? Did they always see the quad 20mm shooting at them? At that time it probably was very common to "get hit by a 20mm".

But was the damage actually of a bigger grenade passing through the wing without exploding, was the damage actually caused by 13mm HE round (used in FW190A8), was the hole in the tail parts of P38s caused by standard HE or actual Minengeschoss? Pretty much open questions don't you think?

Secondly if people got hit by actual 20/30mm Minengeshoss would they be posing by their damaged a/c or were they actuall scattered in the landscape somewhere? We do not know for sure, because some people never RTB'd and they sure did get hit by something. The time line and german beltings and their changes might give us some clue.

I have seen a few reports of 262 hitting a B17 or a Mossie with 30mm round and the plane survived with rather small damage and RTB'd. However I've also seen the 30mm Minen round test on Blenheim and Spitfire fuselage and the pictures of those suggest that you do not survive a 30mm hit in the wing unless the round passes through the wing and detonates after that. That is because the timing of a fuse is a compromise of how deep it penetrates before detonating.

http://me109.sofiacity.com/Waffen/MK108/MK108_pics/mk108blenheim.jpg

So it is actually only a few cases where people DID really know what hit them. If you are hit by a 109G2 you do know what is cannon damage and what is mg damage because of apparent difference. In case 109G6 hits you the difference may be harder to tell, unless you actually get hit by a 30mm MG that is...

The LW guncam shows a few examples of standard gunnery of that era. Only a few hits grazing or even missing altogether. In those guncams you can even see the exploding rounds hit the propellor. But you cannot be sure what rounds actually hit those planes. 13mm HE or 20mm Minen or HE.

Again something by Butch 2k on another board:

C. BELTING AND PREPARATION
1. GENERAL
(1) The deciding factors for the choice of type of ammunition are:
a) The attainment of the greatest possible effect
b) The reasonable ammunition expenditure corresponding to the supply situation

(2) The unit commander, based on the knowledge of the individual types of ammunition, must strive to achieve the best degree of effect in combat by his choice in belting ammunition. At the same time he must understand that ammunition expenditure must be within the limits of the existing supply situation.
(3) The manufacture of ammunition will immediately incorporate in its production process any new knowledge gained at the front or from experimentation. The troops must be aware of the fact however, that at the appearance of a new effective type of ammunition, manufacture can not be changed over at once. The large supply of existing stocks of previously manufactured types of ammunition can not simply be thrown away but must be used up.
(4) New types of ammunition at the start will always be "scarce items." The supply command must be so elastic, however, as to make them available to the troops (in this case under the con¬cept of issuing the newest stocks first, and utilize the older type of ammunition as a reserve and to fill out shortages.
The effort of Development to provide the troops with more effective means of fighting is defeated if these are not issued until the old stocks are used up.
This is especially true of ammunition, wherein an improve¬ment is made within the same type of ammunition.

II. BELTING
Based on combat experiences in conjunction with comparison and effectiveness tests, and in line with the supply situation, the following suggestion for belting the various types of ammunition can be given.
(1) 13mm weapons (MG 131)
1 13mm Br.Spgr.L’Spur o.Zerl (HEIT not self-destroying)
1 13mm Pzgr.L’spur o.Zerl or 13mm Pzbrgr.Patr.(Ph)El o.Zerl (APT or APIT not self-destroying)
(2) 15mm Weapons (MG 151, MG 151 electric primer).
1 15mm Br.Sprgr.L’Spur m.Zerl (HEIT self-destroying)
1 15mm H.Pzgr.o.Zerl (AP not self-destroying.)

(3) 2 cm weapons (MG 151/20, MG 151/20 electric primer, MG-FFM)
a) Fighter Aircraft on Western Front.
1 2cm M.Gesch.Patr.151 m.Zerl (M-projectile, self-destroying)
1 2cm Brgr.Patr.L’spur 151 m.Zerl (Incendiary Tracer self-destroying)
1 Pzgr.Patr.L’spur 151 o.Zerl (APT not self-destroying)
b) Fighter Aircraft on Eastern Front,
3 2cm M-Gesch.Patr. 151 m.Zerl (M-projectile, self-destroying)
1 2cm Brgr.Patr.L’spur 151 m.Zerl (Incendiary Tracer self-destroying)
1 Pzgr.Patr.L’spur 151 o.Zerl (APT not self-destroying)
c) Night Fighters
Same as a) or b) except for night tracer in place of tracer or without tracer or night tracer.
d) Night Fighters with oblique mounted weapons will belt only M-projectile rounds.
e) Bomber, ground-attack, and fighter aircraft in attacking ground targets, ships and boats,
3 2cm M-Gesch.Patr. o.Zerl (M-projectile, not self-destroying)
1 2cm Pz.Sprgr.Patr.o.Zerl (APHET not self-destroying) or 2cm Br.Sprgr.Patr.o.Zerl (HEI not self destroying) or 2cm Pzbrgr.El (or Ph) o.Zerl (API not self destroying)

(In place of the M-projectile rounds and armor-piercing incendiary rounds it is better here to use up existing stocks of high-explosive-incendiary rounds and armor-piercing high explosive rounds),
(If, due to shortages, self-destroying ammunition is used, an attack altitude of at least 800 meters in horizontal flight must be kept.)

(4) 3 cm Weapons (MK 103)
a) Fighter Aircraft.
1 3cm M-Gesch.Patr.L’spur m.Zerl (M-projectile/tracer, self destroying)
1 3cm Bgr.Patr.103 El.o.Zerl (Incendiary, not self-destroying)
b) Bomber, ground-attack, and fighter aircraft in attacking
ground targets.
3 3cm M.Gesch.Patr.o.Zerl (M-projectile not self-destroying). (Here it is preferable to use up 3cm Spgr.Patr.o.Zerl (HE not self-destroying.)
1 3cm Pz.Sprgr.L’spur.o.Zerl (APHET not self-destroying)

In attacking boats
3cm Pzbrgr.Patr.L’spur o.Zerl (APIT not self-destroying)
c) Aircraft for attacking tanks.
1 3cm H-Pzgr.Patr.L’spur.o.Zerl (Special core APT not self-destroying)
Note. - In the case of shortages of some types of ammunition the ammu¬nition listed in parentheses, whose manufacture has been stopped, is to be fired.

In fighting armored ground-attack aircraft such as the IL 2 up to 50% AP ammunition should be belted (however not for 4 motor bombers, since the best results are obtained with blast and incendiary effect against the nacelle.)
(Editors note : this apply to all ammo from 13mm to 30mm where AP shots are available, this is not clear enough given the current tabulation)

(5) 3 cm Weapons (MK 108).
a) Day fighters and night fighters will belt
1 3cm M-Gesch.Patr.o.Zerl (M-projectile not self-destroying) or 3cm M-Brgr.Patr.108 El m.Zerl (M-projectile Incendiary self destroying)
1 3cm Bgr.Patr.108 El. O.Zerl (Incendiary not self destroying)
(or only M-projectiles)
b) Night fighters with oblique mounted weapons will belt only
M-projectile rounds.
Nightfighter munitions use night tracer (Glimmspur).

(6) 3. 7 cm Weapons (3. 7 cm Flak 18, 3. 7 cm Flak 43)
a) Aircraft for attacking ground targets and landing operations,
2 3,7cm Sprgr.Patr.L’spur m.Zerl (HET self-destroying)
1 3,7cm M-Gesch.Patr.L’spur m.Zerl (M-projectile/tracer self-destroying
1 3,7cm Br.Sprgr.Patr.L’spur m.Zerl (HEIT self-destroying)
b) Aircraft for attacking tanks.
Only 3.7cm H.-Pzgr.Patr.L’spur o.Zerl (Tungsten core AP not self-destroying
(7) 5 cm Weapons (5 cm BK).
a) Aircraft for attacking air targets.
Only 5cm M-Gesch.Ptr.Gl’spur BK m.Zerl (M-projectile/night tracer self-destroying)
b) Aircraft for attacking ground targets.
1 5cm Sprgr.Patr.BK o.Zerl (HE not self-destroying)
1 5cm Pzsprgr.Patr.L’spur BK o.Zerl (APHET not self-destroying)
(8) 7.9mm aircraft weapons.
a) MG 17 (Fighters)
5 S.m.K-v (AP - high velocity)
4 P.m.K-v (API - high velocity)
1 B.-Patrone-v (Observation cartridge - high velocity)
and before the last 50 rounds of the belt (as counters)
10 S.m.K L’spur 100/600 (APT high velocity) for day fighting
or
10 S.m.K Gl’spur (APT high velocity night tracer) for night fighting
b) MG 17 (for ground attack use)
MG 81 (flexible and in auxiliary container)
MG 15
2 S.m.E (SAP)
2 S.m.K L’spur 100/600 (APT)
or
2 S.m.K.Gl’spur (APT with night tracer)
2 P.m.K-v or (1 P.m.K-v and 1 B.-Patrone)

I hope Butch don't mind.

So there is some variation in the beltings.

Some other data:

http://www.geocities.com/capecanaveral/hangar/8217/fgun/fgun-am.html

-C+

PS.

"I've heard quite enough Nazi propaganda to recognize it when I see it."

"the masses of biased pseudo-intellectuals with an agenda"

Rrright...