Development of British cannon ammuniation during WW2

[Jukka O. Kauppinen]

What was the timetable for British development for their 20 mm cannon
ammuniation during WW2?

I'm aware that RAF tried to install first cannons to Spit Is but this
was initially a failure. Early Spit V models were introduced with 60
round supply to the Hispanos, later with 120 rounds per gun. Some of the
documents I've seen showed, that RAF had severe problems in 1941 maybe
even during 1942 with HE ammo, which had tendency to explode in the
barrel. Until HE was perfected (42?) I presume the cannons primarily
used the Ball ammuniation?

What is the actual timetable for introduction of various British cannon
ammuniation types for squadron service? Ball from the start, AP, HE, API
etc later?

jok

[Greg Hennessy]

On Sat, 27 Dec 2003 19:08:02 +0200, "Jukka O. Kauppinen"
> wrote:

>
>What was the timetable for British development for their 20 mm cannon
>ammuniation during WW2?
>

Would Dr Williams please pick up the white courtesy phone.... lol!


greg

--
Once you try my burger baby,you'll grow a new thyroid gland.
I said just eat my burger, baby,make you smart as Charlie Chan.
You say the hot sauce can't be beat. Sit back and open wide.

[C Knowles]

Don't know, but I just found this site; might be helpful.
http://www.quarry.nildram.co.uk/


"Jukka O. Kauppinen" > wrote in
message ...
>
> What was the timetable for British development for their 20 mm cannon
> ammuniation during WW2?
>
> I'm aware that RAF tried to install first cannons to Spit Is but this
> was initially a failure. Early Spit V models were introduced with 60
> round supply to the Hispanos, later with 120 rounds per gun. Some of the
> documents I've seen showed, that RAF had severe problems in 1941 maybe
> even during 1942 with HE ammo, which had tendency to explode in the
> barrel. Until HE was perfected (42?) I presume the cannons primarily
> used the Ball ammuniation?
>
> What is the actual timetable for introduction of various British cannon
> ammuniation types for squadron service? Ball from the start, AP, HE, API
> etc later?
>
> jok
>

[Tony Williams]

Greg Hennessy > wrote in message >...
> On Sat, 27 Dec 2003 19:08:02 +0200, "Jukka O. Kauppinen"
> > wrote:
>
> >
> >What was the timetable for British development for their 20 mm cannon
> >ammuniation during WW2?
> >
>
> Would Dr Williams please pick up the white courtesy phone.... lol!

No Doctorate - that's Emmanuel!

The RAF started with HE of French design, but found that the fuze
operated too quickly and tended to detonate on the surface of the
target. They solved this by removing the striker from the fuze and
found out that this provided the right amount of delay. This happened
right at the end of 1940 so was in common use in 1941. Around the
middle of 1941, they changed the filling from HE to HEI, which was
found to be more effective.

They also used ball ammo early on (just an empty steel shell - we'd
call it Target Practice now) in lieu of AP - it would punch through
about a half-inch of plate, and sometimes proved more destructive
initially than the fast-fuze HE. They continued to use ball mixed with
HE/HEI in the belts until 1942, when the SAPI came along. This was
just an HE shell filled with incendiary material and with a hard steel
piercing cap instead of a fuze; it could penetrate around 20mm plate.
From then on, the standard belt mix was two HEI followed by two SAPI.

They were interested in an AP for anti-tank purposes and a
tungsten-cored 20mm APCR was developed by Janecek (of Littlejohn
squeezebore fame). Penetration was spectacular (figures range from
45-65mm) but it seems there were ballistic problems and it was never
adopted. The USAAF had a plain steel AP shot, but AFAIK the RAF never
used one.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

[Peter Kemp]

On or about 27 Dec 2003 19:04:58 -0800,
(Tony Williams) allegedly uttered:


>They were interested in an AP for anti-tank purposes and a
>tungsten-cored 20mm APCR was developed by Janecek (of Littlejohn
>squeezebore fame). Penetration was spectacular (figures range from
>45-65mm) but it seems there were ballistic problems and it was never
>adopted. The USAAF had a plain steel AP shot, but AFAIK the RAF never
>used one.

Tony, fascinating as always, but I have to ask - APCR? Armour Piercing
mumble mumble?

TIA

---
Peter Kemp

Life is short - Drink Faster

[Peter Stickney]

In article >,
Peter Kemp <peter_n_kempathotmaildotcom@> writes:
> On or about 27 Dec 2003 19:04:58 -0800,
> (Tony Williams) allegedly uttered:
>
>
>>They were interested in an AP for anti-tank purposes and a
>>tungsten-cored 20mm APCR was developed by Janecek (of Littlejohn
>>squeezebore fame). Penetration was spectacular (figures range from
>>45-65mm) but it seems there were ballistic problems and it was never
>>adopted. The USAAF had a plain steel AP shot, but AFAIK the RAF never
>>used one.
>
> Tony, fascinating as always, but I have to ask - APCR? Armour Piercing
> mumble mumble?

Armor Piercing Composite Rigid. A dense, hard, penetrating core,
surrounded by a light metal shell to flesh out the shape. It's
generally lighter than a solid shot, so the muzzle velocity is higher.
When it hits, the light sheath is stripped off, and the core, having a
high sectional density, should give more penetration for a particular
velocity. The drawhack is that the lighter shell loses velocity more
quickly than the heavier shot, so that a solid shot is often better
for long range shooting.

Realizing that you didn't really need to have the lightweight sheath
along led to the development of Armor Piercing Discarding Sabot,
(APDS), which drops the sheath (Sabot) on leaving the barrel. The
round then has a better drag/weight ratio, and doesn't lose speed as
quickly.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Johnny Bravo]

On Sat, 27 Dec 2003 22:49:13 -0500, Peter Kemp
<peter_n_kempathotmaildotcom@> wrote:

>On or about 27 Dec 2003 19:04:58 -0800,
(Tony Williams) allegedly uttered:
>
>
>>They were interested in an AP for anti-tank purposes and a
>>tungsten-cored 20mm APCR was developed by Janecek (of Littlejohn
>>squeezebore fame). Penetration was spectacular (figures range from
>>45-65mm) but it seems there were ballistic problems and it was never
>>adopted. The USAAF had a plain steel AP shot, but AFAIK the RAF never
>>used one.
>
>Tony, fascinating as always, but I have to ask - APCR? Armour Piercing
>mumble mumble?

Composite Rigid - a lightweight round with a small hard core
(usually tungsten alloy) for increased armor penetration.


--
"The most merciful thing in the world, I think, is the inability
of the human mind to correlate all its contents." - H.P. Lovecraft

[Henry J. Cobb]

Peter Kemp <peter_n_kempathotmaildotcom@> wrote in message >...
> On or about 27 Dec 2003 19:04:58 -0800,
> (Tony Williams) allegedly uttered:
>
>
> >They were interested in an AP for anti-tank purposes and a
> >tungsten-cored 20mm APCR was developed by Janecek (of Littlejohn
> >squeezebore fame). Penetration was spectacular (figures range from
> >45-65mm) but it seems there were ballistic problems and it was never
> >adopted. The USAAF had a plain steel AP shot, but AFAIK the RAF never
> >used one.
>
> Tony, fascinating as always, but I have to ask - APCR? Armour Piercing
> mumble mumble?

http://www.quarry.nildram.co.uk/Glossary.html
APCR armour piercing, composite, rigid: shot consisting of a
penetrating core (usually of tungsten alloy) enclosed within a
light-alloy body, which travels as a unit to the target

Also you might want to take a look at this:

http://www.quarry.nildram.co.uk/WW2guneffect.htm
WORLD WAR 2 FIGHTER ARMAMENT EFFECTIVENESS

-HJC

[Greg Hennessy]

On 27 Dec 2003 19:04:58 -0800, (Tony
Williams) wrote:


>They were interested in an AP for anti-tank purposes and a
>tungsten-cored 20mm APCR was developed by Janecek (of Littlejohn
>squeezebore fame). Penetration was spectacular (figures range from
>45-65mm)

Fearing Typhoons didnt make wehrmacht AFV crews lives difficult enough!


greg

--
Once you try my burger baby,you'll grow a new thyroid gland.
I said just eat my burger, baby,make you smart as Charlie Chan.
You say the hot sauce can't be beat. Sit back and open wide.

[Jukka O. Kauppinen]

>>>What was the timetable for British development for their 20 mm cannon
>>>ammuniation during WW2?

> They also used ball ammo early on (just an empty steel shell - we'd
> call it Target Practice now) in lieu of AP - it would punch through
> about a half-inch of plate, and sometimes proved more destructive
> initially than the fast-fuze HE. They continued to use ball mixed with
> HE/HEI in the belts until 1942, when the SAPI came along. This was
> just an HE shell filled with incendiary material and with a hard steel
> piercing cap instead of a fuze; it could penetrate around 20mm plate.
> From then on, the standard belt mix was two HEI followed by two SAPI.

Thanks Tony!

So RAF stopped using ball ammo during 1942.
And there was no true AP ammo in use before SAPI?

Interesting. I wonder, they had Hurricane II with 4x20 mm. I presume
this plane was used in ground attack missions with the bombload. Those
cannons were still loaded with HE/HEI/BALL ammo for strafing missions? I
presume they weren't much effective against German armour?

I have Tony/Emmanuel's book and it mentions how RAF tested the cannon
ammo against Japanese tanks. Knowing how Japanese tanks had rather thin
armour I'd guess the results were better against them than against
German armour, excepting Panzer IIs and other light tanks/vehicles?

So RAF *never* had a true AP shot? During whole war? Fascinating.

This development on cannon ammo is a fascinating subject. I was quite
astounded when I interviewed the Finnish ace Antti Tani, who was one of
the best Finnish Morane-Saulnier 406 pilots. They had only HE ammo
available and it is quite wide opinion in Finland, that the Morane
cannon was very problematic. The ammo was so sensitive, that it
sometimes exploded in the cannon barrel - or in the surface of the
target, just like Brits found out. One squadron made tests and mr. Hugo
Estama referred, that the cannon shot exploded even when hitting a
cardboard, before penetrating.

Mr. Tani on the other hand was a quick learner and he actually made AP
ammo by himself. He defused the HE rounds, took out the HE and voila -
self made AP. Similar to British ball? He loaded his cannon himself, 2
HE for 1 "AP". This practise was discontinued by commander's order when
somebody else in the squadron tried making "AP" rounds too and the shot
exploded, wounding him severely. Mr. Tani was a mechanic, watchmaker by
profession, so he knew what he was doing. He claimed total of 7 Soviet
planes with Morane, including two of the most valuable prey out there -
Pe-2 bombers (which almost had higher cruising speed than the Morane's
top level speed).

If your'e interested you can read mr. Tani's interview here:
http://www.virtualpilots.fi/hist/WW2History-TaniHuotariEnglish.html

jok

[Peter Kemp]

On or about Sat, 27 Dec 2003 23:24:54 -0500,
(Peter Stickney) allegedly uttered:

>Armor Piercing Composite Rigid. <snip>

Thanks to all who replied.

---
Peter Kemp

Life is short - Drink Faster

[Guy Alcala]

Peter Kemp wrote:

> On or about Sat, 27 Dec 2003 23:24:54 -0500,
> (Peter Stickney) allegedly uttered:
>
> >Armor Piercing Composite Rigid. <snip>

AKA HVAP for US tank ammo.

Guy

[Tony Williams]

"Jukka O. Kauppinen" > wrote in message >...
>
> So RAF stopped using ball ammo during 1942.
> And there was no true AP ammo in use before SAPI?
>
> Interesting. I wonder, they had Hurricane II with 4x20 mm. I presume
> this plane was used in ground attack missions with the bombload. Those
> cannons were still loaded with HE/HEI/BALL ammo for strafing missions? I
> presume they weren't much effective against German armour?

Several different AP rounds were developed and tested in the UK, but
as far as I can tell they were all unsatisfactory. The Mk 1 and Mk 2
were traditional solid shot and proved ineffective when tested against
tanks, so weren't generally issued. The Mk 3 was the APCR. There was a
more traditional Mk 4, which came out in 1944, but I don't know if
that saw any use; I have no record that it did.

The RAF seemed to find that the ball and SAPI rounds were more than
adequate against aircraft, and the 20mm was too small to do much
damage to tanks. So they concentrated on the 40mm for anti-tank use
until they decided that wasn't good enough either, and went to RPs
instead.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

[Johnny Bravo]

On Sun, 28 Dec 2003 23:02:05 GMT, Guy Alcala
> wrote:

>Peter Kemp wrote:
>
>> On or about Sat, 27 Dec 2003 23:24:54 -0500,
>> (Peter Stickney) allegedly uttered:
>>
>> >Armor Piercing Composite Rigid. <snip>
>
>AKA HVAP for US tank ammo.

It sure beats Composite Rigid Armor Piercing. :)

--
"The most merciful thing in the world, I think, is the inability
of the human mind to correlate all its contents." - H.P. Lovecraft

[Tony Williams]

Johnny Bravo > wrote in message >...
> On Sun, 28 Dec 2003 23:02:05 GMT, Guy Alcala
> > wrote:
>
> >Peter Kemp wrote:
> >
> >> On or about Sat, 27 Dec 2003 23:24:54 -0500,
> >> (Peter Stickney) allegedly uttered:
> >>
> >> >Armor Piercing Composite Rigid. <snip>
> >
> >AKA HVAP for US tank ammo.
>
> It sure beats Composite Rigid Armor Piercing. :)

I have seen a contemporary document in the PRO which refers to it as
exactly that....somebody must have pointed out the obvious and they
changed it fast!

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/