A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Military Aviation
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

WWII 20mm cannon in planes



 
 
Thread Tools Display Modes
  #1  
Old March 8th 04, 06:02 PM
zxcv
external usenet poster
 
Posts: n/a
Default WWII 20mm cannon in planes

It seems to me that the Germans and Japanese had a lot more cannon in their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?


Ads
  #2  
Old March 8th 04, 07:49 PM
steve gallacci
external usenet poster
 
Posts: n/a
Default



zxcv wrote:

It seems to me that the Germans and Japanese had a lot more cannon in their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?


The US .50 BMG was a pretty good gun, reasonable rate of fire, hard
hitting round, and good velocity/range. The German 13mm gun was rather
weak by comparison and 20mm (and later, 30mm and larger) explosive or
incendiary shells were considered good bomber killers, though had
somewhat poorer velocity/range. For most applications, .50 fire was more
than adequate for most combat, especially as you could put more guns and
ammo in the plane compared to 20mm. It wasn't until things like the
toughness of MiG15s in the Korean War and the need for good bomber
killer rounds for US fighters that the limits of the .50 became more of
an issue.
On the other hand, the Brits (and the US Navy?) used 20mm during the war.
  #3  
Old March 8th 04, 07:58 PM
Kevin Brooks
external usenet poster
 
Posts: n/a
Default


"steve gallacci" wrote in message
...


zxcv wrote:

It seems to me that the Germans and Japanese had a lot more cannon in

their
planes than the Americans who seemed to rely almost totally on .50

machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what

type
of projectiles did they fire?


The US .50 BMG was a pretty good gun, reasonable rate of fire, hard
hitting round, and good velocity/range. The German 13mm gun was rather
weak by comparison and 20mm (and later, 30mm and larger) explosive or
incendiary shells were considered good bomber killers, though had
somewhat poorer velocity/range. For most applications, .50 fire was more
than adequate for most combat, especially as you could put more guns and
ammo in the plane compared to 20mm. It wasn't until things like the
toughness of MiG15s in the Korean War and the need for good bomber
killer rounds for US fighters that the limits of the .50 became more of
an issue.
On the other hand, the Brits (and the US Navy?) used 20mm during the war.


The USN started to switch to the 20mm during the latter part of the war, but
it also produced .50 cal armed aircraft through the end of the war, too. If
the original poster will do a search using google news, he will find that
this topic has repeatedly been beat to death in this NG, and likely find
some items of interest to him.

Brooks


  #4  
Old March 8th 04, 08:24 PM
Keith Willshaw
external usenet poster
 
Posts: n/a
Default


"zxcv" wrote in message
...
It seems to me that the Germans and Japanese had a lot more cannon in

their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?



Because most continental powers were using .30 calibre MG's and often
only mounted 2 or 4 of them which gave pretty poor firepower

4 or 6 .50's give a much better armament and less incentive to
move to cannon. Various calibre cannon were tried with some success
and towards the end of WW2 the USN started to adopt it more
rapidly.

Keith


  #5  
Old March 8th 04, 11:23 PM
Cub Driver
external usenet poster
 
Posts: n/a
Default


The American fifty-caliber machinegun was a formidable weapon,
especially against fighters. This size bullet was rarely used by other
nations, who tended to favor rifle-caliber (.30-cal or 7.x mm)
machineguns. The A6M2 Zero had two rifle-caliber guns and two 20 mm
cannon. The Wildcat with four fifties came out even against the Zero
during the first year of the war, despite the fact that the U.S.
pilots started out with the disadvantage of no combat experience. And
the Wildcat wasn't even considered a first-class American fighter!

When Germany and Japan realized they had to up-gun their fighters in
order to prevail against heavily defended and armored American
bombers, they naturally favored cannon. After the first year of the
war, the U.S. didn't have to contend much with enemy bombers; the
Americans were on the offensive, and U.S. fighters mostly battled
enemy fighters.

It seems to me that the Germans and Japanese had a lot more cannon in their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?


all the best -- Dan Ford
email: (requires authentication)

see the Warbird's Forum at
www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com
  #6  
Old March 9th 04, 01:10 AM
pendell
external usenet poster
 
Posts: n/a
Default

"zxcv" wrote in message ...
It seems to me that the Germans and Japanese had a lot more cannon in their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?


Question for the group at large ...

.... did it have anything to do with the fact that the Germans were
gunning for B-17s and such, and therefore needed a weapon that had a
low rate of fire and less accuracy but a heavy punch? Whereas the
Americans, whose fighters mostly did escort over europe, needed a
weapon with better accuracy and a higher rof?

Just curious.

Respectfully,

Brian P.
  #7  
Old March 9th 04, 06:52 AM
Tony Williams
external usenet poster
 
Posts: n/a
Default

"zxcv" wrote in message ...
It seems to me that the Germans and Japanese had a lot more cannon in their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?


See: http://www.quarry.nildram.co.uk/WW2guneffect.htm for full details
of WW2 fighter guns and ammunition, and a comparison of their
effectiveness.

As other responders have said, the .50 was a good gun which met USAAF
needs (although the USN would have preferred to make more use of the
20mm). Other nations preferred to use cannon as they were more
destructive, even when (like the USSR) they had a good HMG available.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/
  #8  
Old March 9th 04, 07:28 AM
ArtKramr
external usenet poster
 
Posts: n/a
Default

Subject: WWII 20mm cannon in planes
From: (Tony Williams)
Date: 3/8/04 9:52 PM Pacific Standard Time
Message-id:

"zxcv" wrote in message
...
It seems to me that the Germans and Japanese had a lot more cannon in their
planes than the Americans who seemed to rely almost totally on .50 machine
guns.

Why was that? What was the rate of fire or the 20mm cannons and what type
of projectiles did they fire?


See:
http://www.quarry.nildram.co.uk/WW2guneffect.htm for full details
of WW2 fighter guns and ammunition, and a comparison of their
effectiveness.

As other responders have said, the .50 was a good gun which met USAAF
needs (although the USN would have preferred to make more use of the
20mm). Other nations preferred to use cannon as they were more
destructive, even when (like the USSR) they had a good HMG available.

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



Seems lik there was a lot of indecision about our use of canons, When we were
told that our Marauders were being replaced by Invaders they also announced
that the Invaders would come with a 75mm cannon mounted in the nose. We got
the Invaders OK but nary a cannon in sight, We didn't have much to complain
about since it had 14 50's firing forward. But I alway s looked forward to
using that 75mm cannon and was sorry when they didn't arrive, I think one
reason was it had to be hand fed by a guy in the right seat which would have
given it a very slow rate of fire.When we flew warhead A-26's I was the guy in
the right seat. I only flew in the nose on Norden equipped models.II sure
would have loved to have had the 75mm cannon to play with. (sigh)


Arthur Kramer
344th BG 494th BS
England, France, Belgium, Holland, Germany
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

  #10  
Old March 10th 04, 12:42 AM
zxcv
external usenet poster
 
Posts: n/a
Default

"Emmanuel Gustin" wrote in message
...
"pendell" wrote in message
om...

... did it have anything to do with the fact that the Germans were
gunning for B-17s and such, and therefore needed a weapon that had a
low rate of fire and less accuracy but a heavy punch?


Like most WWII weapons, the 20 mm cannon were developed
during peacetime, a considerable time before the first B-17s
appeared over Europe. Combat experience did not play a large
role in to the decision. (There was of course some experience in
Spain and China.) It was more a matter of, as engineering usually
is, balancing different factors to find the optimum. The big factors
were destructiveness, hit probability (rate of fire and muzzle
velocity) and weight. The first favours bigger guns, the second
usually favours smaller-calibre weapons, and the third generally
favours bigger guns again (although they are heavier, they give
more hitting power for the same installation weight; for example,
a single .50 is equivalent to about four .30 Brownings.)

The wide consensus during WWII was that the optimum was
around 20mm. Given the same technology, rate of fire and muzzle
velocity were not much lower; the gun was heavier but the
ammunition far more effective. Later several heavy machine guns
were modified to 20 mm cannon (the Soviet ShVAK and B-20, the
German MG 151/20, and the Japanese Ho-5) because they were
judged to be more effective in that form. The USAAF did not follow,
in part because of a different doctrine, and in part because its gun
development budgets between the wars were largely hypothetical
in nature.

Whereas the Americans, whose fighters mostly did escort over
europe, needed a weapon with better accuracy and a higher rof?


It was less a matter of what they needed than what they had. But
the big advantage of the .50 was that a large stock of ammunition
could be carried. A good 20mm cannon would have offered similar
rates of fire and accuracy (although with the limitation that only
four would have been installed instead of six) and more firepower,
but the total available firing time would have been much shorter.
For an escort fighter that was a very important consideration. For
this reason, for example, the USAF decided against a plan to install
four 20mm cannon in the nose of the P-38: The .50s had 500 rounds
(40 seconds of fire) but the cannon only 150 (15 seconds).

--
Emmanuel Gustin
Emmanuel.Gustin -rem@ve- skynet dot be
Flying Guns Page: http://users.skynet.be/Emmanuel.Gustin/





What about planes with multiple fixed guns that had different amounts of
ammunition/fire time -- did the pilot have a selector to determine which
guns would fire or did everything fire when the trigger was pulled and some
guns would run out first?


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: 1989 "War Planes" (Of The World) Cards with Box J.R. Sinclair Aviation Marketplace 0 December 30th 04 12:16 PM
Conspiracy Theorists (amusing) Grantland Military Aviation 1 October 2nd 03 12:17 AM
Vitre d'avion de la WWII ? WWII planes panes ? Dessocea Military Aviation 0 August 15th 03 07:07 PM
Panes of planes of the WWII? Dessocea Military Aviation 0 August 15th 03 06:59 PM
FS Books USAF, Navy, Marine pilots and planes Ken Insch Military Aviation 0 July 20th 03 02:36 AM


All times are GMT +1. The time now is 02:39 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ©2004-2014 AviationBanter.
The comments are property of their posters.