The Mysterious "De Wilde Shell"
Edward L. Prichard
first ran across a
reference to it in Churchill's "Their Finest Hour," when he mentions the
pilots fighting the Battle of Britian were complaining about the shortage of
"the De Wilde ammunition." I have looked all over and have compiled a
pitiful amount of information on this .303 bullet for the standard British
Browning aircraft machine gun. Here is what I have been able to find out:
De Wilde was Swiss and demonstrated his "explosive bullet" to the RAF
shortly
before the war. The design was very shaky, sometimes exploding in the gun
barrel, and othertimes failing to explode at all. But the design was much
improved by one Dixon (hence "Dixon-De Wilde"). Dixon, with the aid of a
chemist, crafted a better explosive compound for the bullet, and a reliable
detonator (inertial: a ball-bearing strikes an percussion cap and anvil)
that fit into a softer bullet nose. It was used in combat, but did suffer
shortages. Often, (I have read) only one of the eight guns of the Spitfires
and Hurricanes were loaded with "De Wilde Shell" when it was available (the
name was kept in the hope that the Germans would think it was the old,
unreliable design that they knew about too). The deservedly famous BofB
fighter pilot Max Aitken said of the De Wilde that "there was nothing that
flew in the war that could stand up to it."
And there you have it. That is all I know. many questions remain to worry
me: what was the "explosive" and how much was in a round? The detonator
details? Ballistics? Range of use in the war? Tests of its effectiveness?
Was it used throughout the war? In bombers? (Len Deighton has written that
Ju-88 night fighters were not hesitant about flying into the fire of the 4
..303 guns in the tails of British Bombers, but it seems to me that if the
turrets were firing De Wilde, they might have had another think.)
There has been much comment on limited effectiveness of the British
..303 against bombers during the war, and Dowding led the move to the 20mm
cannon wherever and whenever possible, (after the war in a Times special
section, he did refer to the excellent performance of the De Wilde Shell),
but the .303 soldiered on until the 4 .303 in the Spitfire IX were finally
replaced with .50 Brownings in later
models. Of course the .303 remained in service to the end, continuing to
fly in British bombers, etc.
But if Aitken is right, this puts an entirely new face on the evolution of
aircraft armament and the effectiveness of British aircraft in combat. The
DeWilde was designed to blow up--or open--self-sealing gas tanks, and this
type of round coming out of a machine gun at 1200 rounds per minute could
certainly raise hell, but I am yet to discover further information. Can you
point me to any references?
Emmanuel Gustin
>unreliable design that they knew about too). The deservedly famous BofB
>fighter pilot Max Aitken said of the De Wilde that "there was nothing that
>flew in the war that could stand up to it."
The mystery is perhaps why the reputation of the De Wilde
round became so great. After all, incendiary ammunition for
rifle-calibre guns was not new; it's development dated back
to WWI. Most combattants used it; I have been told that the
Japanese even developed and used HE/I ammunition in this
calibre!
The effectiveness of the .303 incendiary was limited because
(1) it could not penetrate much armour; (2) it did not make a
very large hole in a fuel tank, so a fire could only occur if the
tank already contained a suitable gas/oxygen mixture (and more
and more often tanks were pressurised with cooled and filtered
exhaust gases); (3) after going through the metal skinning of an
aircraft the projectile was likely to tumble, losing even more of its
hitting power -- an effect that was more important if the target was
a large bomber.
I remember reading somewhere that the largest advantage of the
De Wilde was that pilots could see the small explosions when they
hit the target; and that this assisted greatly in aiming (tracer did not
have the same effectiveness, because it had a different trajectory).
But I have not found back the original quote.
>Was it used throughout the war? In bombers? (Len Deighton has written
that
>Ju-88 night fighters were not hesitant about flying into the fire of the 4
>..303 guns in the tails of British Bombers, but it seems to me that if the
>turrets were firing De Wilde, they might have had another think.)
As far as I know, at the end of the war only incendiary ammunition
was used by the .303 turrets in bombers. I don't know whether this
was still the "De Wilde" design. There was no point in loading AP,
because this could not penetrate the armour of modern fighters,
anyway.
As for nightfighters being "not hesitant" to fly in the fire of the
.303 guns, they probably set through their attack even if fired
on, knowing that the accuracy and hitting power of the turrets
were small, and that breaking off might be more dangerous
than continuing: They had armoured windscreens, but most of
the cockpit's glazing was NOT armoured, and fire from above
was really dangerous.
>There has been much comment on limited effectiveness of the
>British .303 against bombers during the war, and Dowding led
>the move to the 20mm cannon wherever and whenever possible,
The move to 20mm was described in some official document
as a precaution against "the Germans armouring the back of
their engines". The amount of armour plate in WWII combat
aircraft steadily increased, and the .303 was obviously deficient
in AP performance.
>but the .303 soldiered on until the 4 .303 in the Spitfire IX were finally
>replaced with .50 Brownings in later models.
Incidentally, concerns about the effectiveness of rifle-calibre
guns already arose during WWI, when many aircraft returned
home with a lot of small bullet holes in them. This prompted the
development of .50 guns in both Britain and the USA, but
while the USA finally adopted the Browning .50, the RAF
committee decided in 1929 (they certainly took their time!)
to retain .303 weapons. No British .50 gun was available
(although some were developed) and deliveries of the
Browning .50 M2 were hard to get.
>The DeWilde was designed to blow up--or open--self-sealing
>gas tanks,
That was the goal of many ammunition designers, but it
was not one that was easily achieved. I believe the "last
word" on this in WWII was German 30mm ammunition
with hydrostatic fuses, so that it only exploded inside
fuel tanks...
Emmanuel Gustin
Taki Kogoma
message <71pi65$rqg$1...@fu-berlin.de> to soc.history.war.world-war-ii:
>I remember reading somewhere that the largest advantage of the
>De Wilde was that pilots could see the small explosions when they
>hit the target; and that this assisted greatly in aiming (tracer did not
>have the same effectiveness, because it had a different trajectory).
>But I have not found back the original quote.
I think I read something to this effect in either _Fighter_ or _The Battle
of Britain_ (both by Deighton).
--
Capt. Gym Z. Quirk | "I'll get a life when someone
(Known to some as Taki Kogoma) | demonstrates that it would be
quirk @ swcp.com | superior to what I have now."
Veteran of the '91 sf-lovers re-org. | -- Gym Quirk
nightjar
Edward L. Prichard wrote in message
>...Of course the .303 remained in service to the end, continuing to
>fly in British bombers, etc.
>
My father was RAF ground crew and would sometimes wander around the
dispersal areas picking up the ammo that was ejected when the gunners
cleared their guns before take-off. According to him the bombers' machine
guns were loaded with a repeating pattern of five different types of
ammo - ball, day tracer, night tracer, AP and incendiary. Whether that
continued throughout the war, the use of day tracer in particular, I
cannot say, nor is he any longer available to ask.
Nightjar
Rob Davis
> Now I have one for all you ammunition experts: "The DeWilde Shell." I
> first ran across a
You should read NINE LIVES by G/Cpt Alan C Deere DSO OBE DFC
(Hodder 1959) SBN 340 01441 5. I quote:-
"At the time as this harmonization was agreed [at 250 yards], a
new type of incendiary ammunition was introduced into the
Command, in limited supply. It was known to the pilots as "De
Wilde" ammunition, a name with a faintly foreign, and therefore
mysterious, ring. In fact, we were given to understand that it
was a Belgian invention, which had been brought to England on the
fall of that country. Production was not fully under way, hence
the limited supplies. De Wilde unlike the standard incendiary
ammunition in use, was without and flame or smoke trace. Its
greatest value lay in the fact that it produced a small flash on
impact thus providing to the attacking fighter pilot that his aim
was good. In the official [The London Gazette of 10-Sep-41]
despatch on the Battle of Britain, Air Marshal Dowding said 'De
Wilde ammunition became available in increasing quantities ...
and it is extremely popular with the pilots, who attributed to it
almost magical properties.' With all due respect to Lord
Dowding, this was not strictly true. As I have said, its great
value lay in the fact that, for the first time pilots were able
confirm their aim; a most important consideration in the
conservation of ammunition and the delivery of the coup de grace.
"It was not until some three years after the war that I learned
the true story of this ammunition. Far from being a foreign
invention, the De Wilde incendiary bullet was the design of
Brigadier Dixon, a Ministry of Supply expert. Why the
introduction of this ammunition was shrouded in secrecy to the
extent of giving it a foreign sounding name is a mystery, even to
the designer who was eventually rewarded by the Royal Commission
of Awards in recognition of his achievement. I amp leased to
record that I was one of the many pilots who supported his
claim."
Phew! I'll send you the bill for the RSI treatment...
Rob Davis MSc MIAP
Anstey, Leicester UK. 0976 379489
Martin Rapier
{snip}
>Browning aircraft machine gun. Here is what I have been able to find out:
>De Wilde was Swiss and demonstrated his "explosive bullet" to the RAF
>shortly
AFAIK the De Wilde ammo was just simple tracer ammo - useful for accurate
aiming and setting fuel tanks on fire. It wasn't MG calibre cannon ammo!
Cheers
Martin
--
Martin Rapier, Database Administrator
Corporate Information & Computing Services.
University of Sheffield Tel 0114 222 1137
The opinions expressed here may be those of my employer, or they may not.
http://rhino.shef.ac.uk:3001/mr-home/
Richard Becker
>
> My father was RAF ground crew and would sometimes wander around the
> dispersal areas picking up the ammo that was ejected when the gunners
> cleared their guns before take-off. According to him the bombers' machine
> guns were loaded with a repeating pattern of five different types of
> ammo - ball, day tracer, night tracer, AP and incendiary. Whether that
> continued throughout the war, the use of day tracer in particular, I
> cannot say, nor is he any longer available to ask.
>
Did the AAF use an incendiary round in their .50 cal sequence?
What was the .50 cal sequence on 8th AF fighters? B-17 & 24 defensive
.50 cals?
Were there any "marking" or tracer rounds for the British 20mm?
Inquiring minds want to know!
rgds,
RB
Edward L. Prichard
>first ran across a
>pilots fighting the Battle of Britian were complaining about the shortage
of
Thanks very much for your opinions. They were not very helpful, however,
because they lacked references. Would further communicatants provide the
minimal scholastic bibliographic material, please? Please do not be
offended, but I must point out that the amount of opinionated and
unreferenced information (and misinformation) in this newsgroup is rather
large.
I must hope that this newgroup is about historical accuracy and not
egotistical and unreferenced opinion. At least some could read the original
submissions more carefully
Thanks again,
Ed
Emmanuel Gustin
>Thanks very much for your opinions. They were not very helpful, however,
>because they lacked references. Would further communicatants provide the
>minimal scholastic bibliographic material, please?
Let's see... Someone else has found the reference to my
comment on the DeWilde itself, so I won't bother.
My reference to the Hispano being needed in case
the Germans "armoured the back of their engines" was from a
report by Dowding himself, quoted by Alfred Price in "The Spitfire
Story". Dowding tried to explain why the development of the
Spitfire Mk.IB was necessary.
My remarks on the effectiveness of small-calibre incendiary
rounds were based A.D.I.(K) Report No.11/1946, of which
I have an excerpt. This report summarized German
developments of ammunition and guns. Their original
incendiary round was a phosphorus round that started
burning when fired. They later developed a "delayed burn"
round similar in effect to the DeWilde, based on the
B-Geschoss --- a 7.92mm explosive round.
Incidentally, according to this source the Germans ran
ground tests with a Stirling, and discovered that even
20mm incendiary rounds would not penetrate its fuel
tanks! That source also mentions the development of
30mm rounds with hydrostatic fuses.
Comments on the development of .50 guns being prompted
by unsatisfactory performance of the .303 during WWI:
See "British Aircraft Armament volume 2" by R. Wallace
Clarke.
>I must hope that this newgroup is about historical accuracy and not
>egotistical and unreferenced opinion.
Yes, but on the other hand you must realise that providing
detailed biographical references is bound to be a fair
amount of work.
Emmanuel Gustin <gus...@NoSpam.uia.ac.be>
(Delete NoSpam. from my address. If you can't reach me, your host
may be on our spam filter list. Check http://hipe.uia.ac.be/Spam/.)
nightjar
Richard Becker wrote in message <3642CE...@sprintmail.com>...
>What are these day and night tracer rounds?
All my father said was that day tracers left a smoke trail while night
tracers glowed. ISTR having seen some fighter gun camera shots that appear
to show smoke tracers while the stream of glowing night tracers is a
fairly familiar image from many wartime films and films about the war.
Colin Bignell
KNC
:
There is a good account of the De Wilde bullet in an altogether
fascinating book; "The Eternal Summer" by Ralph Barker pp1-17
Published by Collins (199 ISBN 0 00 215585 0)
di...@nospamstable.demon.co.uk
East Anglia: The Air War
http://www.stable.demon.co.uk
Semper in excretum solus profundus variat
On 3 Nov 1998 16:21:09 GMT, "Edward L. Prichard" <ed...@teleport.com>
wrote:
Now I have one for all you ammunition experts: "The DeWilde Shell." I
first ran across a
reference to it in Churchill's "Their Finest Hour," when he mentions the
pilots fighting the Battle of Britian were complaining about the shortage of
"the De Wilde ammunition."
Emmanuel Gustin
>All my father said was that day tracers left a smoke trail while night
>tracers glowed.
Germans called day tracers "light trace" and night tracers
"glow trace". Apparently day tracers were too bright, and
likely to reduce the night vision of the crew. They also had
phosphorus-with-hard-core rounds, likely to leave a smoke
trail.
BTW, the Germans called their equivalent of the De Wilde
the B-Geschoss -- B for "Beobachtung", observation. It
had a small explosive charge and a load of incendiary
material.
Alan Brennan
di...@stable.demon.co.uk says...
designed to give off a flash of light when they hit anything, thereby
showing a fighter pilot whether he was hitting his target or not.
>
>
>
>
Edward L. Prichard
Emmanuel Gustin wrote in message <7205to$qac$1...@nntp6.u.washington.edu>...
>Yes, but on the other hand you must realise that providing
>detailed biographical references is bound to be a fair
>amount of work.
>
>
Thank you very much for the references. I had overlooked the one in
"Spitfire Story," and the ref on the Stirling wing tanks is terrific.
Thanks again. As to references, I did not mean to come across as stickler.
Sure there is a place for just discussion and chat, but if someone goes to
the trouble to answer a question, references should not take too much
work--even a hint in a direction would help. Of course, if you are Alfred
Price, William Green, John Alcorn, etc., this does not apply. thanks again.
Ed
Irwin Probstein
>
> Emmanuel Gustin wrote in message <7205to$qac$1...@nntp6.u.washington.edu>...
interest in that aircraft. Can you tell me more about that reference -
wingtanks etc.? Thanks Irwin