Why .50 cal machine guns in USA WW2 Fighters?
Midnight Lurker
on all of their fighters and bombers in World War II when there were 20
Millimeter machine cannon available. I know that the P-39 had a .37 mm
cannon that fired through its propeller hub and that the P-38 had a 20 mm
cannon in its nose. But the P-39 was not an effective fighter and was
palmed off on the Russians and the P-38 also had 4 .50 browning machine
guns in it's nose. I even remember reading about a P-38 being fitted with
a 75 mm single shot cannon that the pilot had to load between his legs.
The P-51, -47, F4U, F6F, etc all used up to 8 .50 cal machine guns. As
well as the B-17's, B-24's, etc on the Bomber force. I believe even the
early B- 47's and B-52's had .50's in their tails and they weren't built
until well after the war.
Was the .50 cal the only thing we had available? The Japanese used 20 mm
cannon on their fighters and I believe the ME-109 also had cannon on it?
Thanks in advance.
Larry Ries
Keith Willshaw
Midnight Lurker <em...@microsoft.com> wrote in message
news:01bee4a9$642058c0$2550...@unit3ws01.comp.pge.com...
> I have a question for the group. Why did the US military use .50 cal guns
> on all of their fighters and bombers in World War II when there were 20
> Millimeter machine cannon available. I know that the P-39 had a .37 mm
> cannon that fired through its propeller hub and that the P-38 had a 20 mm
> cannon in its nose. But the P-39 was not an effective fighter and was
> palmed off on the Russians and the P-38 also had 4 .50 browning machine
> guns in it's nose. I even remember reading about a P-38 being fitted with
> a 75 mm single shot cannon that the pilot had to load between his legs.
I recommend you read Emmanuel Gustin's Excellent page at
http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-fr.html
This is a wonderful resource with a valuable list of
source material.
Keith
Scott Chan
>
> I have a question for the group. Why did the US military use .50 cal guns
> on all of their fighters and bombers in World War II when there were 20
> Millimeter machine cannon available.
There are many factors (throw weight, ballistics, reliability, cost,
weight
etc), but consider that the Germans and Japanese had to
defend against large bombers while the Americans never faced that kind
of
opposition. The .50 was more than adequate to shred a Japanese or
German
opponent. A cannon is more suited to knocking down B-29s and
B-17s.
Several US fighters did have 20mm cannons: The P-38 had 1 20mm in
addition
to four 0.50 MG. Some F4U Corsairs and F6F Hellcats carried 4x20mm
instead
of machine guns. Presumably these were better suited for ground attack,
since their aerial opposition was very lightweight.
Indiana Joe
Lurker" <em...@microsoft.com> wrote:
>I have a question for the group. Why did the US military use .50 cal guns
>on all of their fighters and bombers in World War II when there were 20
>Millimeter machine cannon available. I know that the P-39 had a .37 mm
>cannon that fired through its propeller hub and that the P-38 had a 20 mm
>cannon in its nose. But the P-39 was not an effective fighter and was
>palmed off on the Russians and the P-38 also had 4 .50 browning machine
>guns in it's nose. I even remember reading about a P-38 being fitted with
>a 75 mm single shot cannon that the pilot had to load between his legs.
That was a design study, it never got to the prototype stage.
>The P-51, -47, F4U, F6F, etc all used up to 8 .50 cal machine guns. As
>well as the B-17's, B-24's, etc on the Bomber force. I believe even the
>early B- 47's and B-52's had .50's in their tails and they weren't built
>until well after the war.
>
>Was the .50 cal the only thing we had available? The Japanese used 20 mm
>cannon on their fighters and I believe the ME-109 also had cannon on it?
Several reasons. First, it was very reliable, more so than cannons or
even other machine guns. Second, you could carry a lot of ammunition for
it, you rarely worried about runing out. Third, it still hit pretty hard
(compared to the .30-cal used in many European or Japanese fighters.
Fourth, it was smaller than a cannon, you could carry six or eight instead
of 1 or 2. Finally, many of the cannons used were fairly short-ranged (due
to short barrels), and the Browning .50 outranged them.
The M2 machine gun was a good weapon, don't discount it just because of
its size.
--
Joe Claffey | "Make no small plans."
jr...@home.net | -- Daniel Burnham
Yevgeniy Chizhikov
Indiana Joe wrote:
> Several reasons. First, it was very reliable, more so than cannons or
> even other machine guns. Second, you could carry a lot of ammunition for
> it, you rarely worried about runing out. Third, it still hit pretty hard
> (compared to the .30-cal used in many European or Japanese fighters.
Most Japanese fighters used cannons.
> Fourth, it was smaller than a cannon, you could carry six or eight instead
> of 1 or 2. Finally, many of the cannons used were fairly short-ranged (due
> to short barrels), and the Browning .50 outranged them.
Not true, see Soviet ShVAK and B-20 cannons. They were lighter than Browning
amd had higher rate of fire. Muzzle velocity was simular. German, Japanese, and
British cannons were also very good, not much heavier than 0.50 and had rate of
fire very similar.
Yevgeniy Chizhikov.
Steve Hagarty
(bigger is not always better). Overall I think that the US was stuck with
using the .50cal because of the availability, versatility, the API round,
logistics and not having to engage heavy/medium enemy bombers. Here are some
facts I know about the US .50cal MG as compared to the German MG151/20 and
the advantage of having 6x .50cal MG rather than 4x 20mm cannons on a US
fighter aircraft (correct me if they are inaccurate, I did not go into my
reference materials to quote specific figures but am going by my excellent
memory):
The US fighters did not need cannon shells to destroy German or Japanese
fighters. Cannons were more effective against heavy/medium bombers of which
we were not going up against in Europe or the Pacific. I'm sure there were
many cases where an enemy aircraft got away damaged where it may have caught
fire or exploded if hit by a lesser number of 20mm rounds but a damaged
aircraft was also a "Mission Kill" and you did not have to worry about it
shooting back at you.
The .50cal had a higher muzzle velocity and flatter trajectory than the 20mm
making it easier to hit the target, especially in deflection shots. It is a
VERY accurate round, almost too accurate, not good dispersion for an area
fire MG but makes a great sniper round out to 2,000 yards.
Very good penetration. The .50cal AP/API could penetrate the 6-8mm seat
armor of a fighter from about 300-400 yards. In order to counter the armor
piercing qualities of the .50cal the Germans had to put 12mm seat armor in
the TA-152 which was normally 6-8mm thick in earlier fighter aircraft.
You can carry a lot more .50cal ammo than 20mm. The early FW-190 and Bf-109E
only had 60 round drums for their MG-FF 20mm. Later models Bf-109 and FW-190
models only carried 120-150 MG151/20 20mm rounds per gun. The larger ammo
load allowed US fighter escort aircraft over Europe to engage German
interceptors AND make multiple strafing attacks on targets of opportunity on
the way back to England. I do not think they could have achieved the LEVEL
of damage with 20mm cannons although the DESTRUCTIVENESS of the 20mm would
have been greater on ground targets. Look how many German fighters were
destroyed on the ground!
I'd say the .50cal was better at suppressing AA sites at German airfields
and other installations during ground strafing.
Bomber crews could put out a higher volume of fire and carry more ammo than
a 20mm and use them in twin turrets and hand held. The higher volume of fire
and flat trajectory allowed newer pilots/gunners to obtain more hits. The
way we rotated pilots/crew back to the US (was it 300 hours over continent
for fighter pilots and 25 missions for bomber aircrews stationed in England)
they were going back home just when their gunnery would have improved to the
point of taking advantage of the 20mm. I am pretty sure the effective range
of the .50cal equal or exceeded the German MG151/20.
Rate of fire was 10-12 rounds per second for the .50cal as compared to 8-10
for a 20mm. A one second burst from 6x .50cal MG's would put out 60-72
rounds as compared to 32-40 rounds for 4x 20mm cannons. Most pilots in WWII
liked the VOLUME of fire as a trade off to lethality. This was very
important in high angle deflection shooting where the target was really
flying THROUGH airspace filled with projectiles as opposed to being tracked
and fired on and correcting after each burst. Most deflection shooting
involved putting a volume of fire ahead of the target and hoping he flies
through it and gets hit by some bullets. Based on the above computation the
target would be hit by 40-50% more rounds of .50cal than 20mm flying through
the same airspace. The tail gunners of a 12 bomber formation (24x .50cal
guns) could put out about 250 rounds per second. If they had one 20mm
cannon in the tail they could only put out 96-120 rounds per second. Even
without hitting an incoming fighter the psychological effect of SEEING so
many rounds (tracers) coming at you was a great deterrent. In a tail attack
a German pilot was exposed to defensive fire for about 4-6 seconds (longer
if he closed in to point blank range) meaning that almost 1,500 rounds would
have been fired in his direction. No wonder they went to head-on attacks! I
do not think that German pilots cared whether they were 20mm or .50cal, it
still had the same effect. Volume has a greater effect than lethality in
this case. A .50cal tail gunner in a bomber could open fire on a German
interceptor before the German was in range to open up with his 20mm even if
he was just spraying rounds at him it caught the German pilots attention.
This was partially due to the German having to chase the bomber.
I think the advantage the Germans had with the MG151/20 was in the Bf-109.
It was very easy to line up a shot accurately and concentrate rounds into a
small area by having the gun fire through the prop. The disadvantage for the
P-47 and P-51 was having to set the wing guns to converge at a certain point
ahead of the aircraft. Supposedly at 300 yards the guns from both wings
would put their rounds into a four foot grouping. At very close range (under
50 yards) American pilots had to line the shot up with the guns from only
one wing. At close range with a small deflection I'd rather have a single
20mm firing through the nose than six or eight .50cal guns. Since about 80%
of the Air-Air kills were made at close range on targets that never saw
their attacker an argument could be made that the 20mm would have been a
better choice. I could agree somewhat there but only if you had one or two
firing through the prop, which could NOT have been the case with the US
fighters. If you were a fighter coming up on an unsuspecting target from his
6 O'clock or out of the sun and were lined up for a clean and close shot I'd
say the any number of 20mm guns would dispatch him as quickly as 6x .50cal
but the .50cal would still make the kill in most cases.
The .50cal API (Armor Piercing Incendiary) round was very effective. It
could rip through any part of an aircraft and ignite fuel, oil and hydraulic
fluids. Cannon shells did not typically penetrate very far into an aircraft
and affected only the area it hit. Cannon shells were not always effective.
Sometimes they exploded on contact with the outer skin of the aircraft
causing superficial damage. The fusing of the shell was very important. An
AP round can go through multiple systems on an aircraft ricocheting around
and causing damage before being stopped by something like an engine, armor
or body part. I think that if it were not for the great armor piercing and
incendiary quality of the .50cal bullet itself it would have been an average
performer. I think that pilots/gunners used about 30-40% load of API and the
rest AP and Ball (maybe Tracer but many discontinued using Tracers later in
the War except for bomber gunners).
Logistics was likely another reason. In sending ammo overseas (Europe and
Pacific) there was a multitude of .50cal MG on ground tanks/vehicles/AA and
used by the infantry that needed the ammo so it was never a scarce item. I
do not think that there were very many ground units that used the 20mm. I
also think the .50cal was good enough to get the job done at the start of
the war so there was no urgent need to get a replacement. I think that in
1940 the only reliable 20mm cannon the Allies had was the Bofors and
Hispano-Suzia, neither of which was designed in the US although we did
manufacture them on license. There may have been a greater need to use the
available 20mm cannons as AA guns on combat and merchant ships. Overall I do
not think that putting 20mm cannons on US aircraft would have made them more
effective but in some cases they could have been more effective with a
cannon armed aircraft.
I think that the German aircraft usually has a 20% HE load with the other
80% split between Ball and Tracer rounds so not every hit is going to be an
explosion. I do not think the German Incendiary round was as effective as
the US one. I think in the last few weeks of the war the US developed a
"Super Incendiary" round for the .50cal and increased the lethality even
greater. The 30mm cannons may have been all HE but had a low rate of fire
and high trajectory. Not ideal for going against fighters but great against
bombers. The Russian 23mm cannon was a very effective weapon with a high
rate of fire and lethal destructiveness but again, a low ammo load. I'd rate
it better than the German MG151/20. Especially the way the Russians used it
with 1-3 firing through the prop. I think the Allied and German 20mm cannons
had almost identical performance. The German 20mm MG151/20 was developed
from the 15mm MG151/15 around 1940(?) and was not used in the Battle of
Britain and only somewhat in Operation Barbarossa.
I'm sure there are other areas where the 20mm was superior but the .50cal
got the job done and PROBABLY accounted for more aircraft destroyed (on
ground and in air) than any other caliber in WWII (Europe, Pacific, CBI,
North Africa). Hey, the .50cal has been in front line service with hardly
any modifications (I think only one) for over 80 years and I do not think
they have a replacement lined up for it!!!
Steve Hagarty
Midnight Lurker <em...@microsoft.com> wrote in message
news:01bee4a9$642058c0$2550...@unit3ws01.comp.pge.com...
> I have a question for the group. Why did the US military use .50 cal guns
> on all of their fighters and bombers in World War II when there were 20
> Millimeter machine cannon available. I know that the P-39 had a .37 mm
> cannon that fired through its propeller hub and that the P-38 had a 20 mm
> cannon in its nose. But the P-39 was not an effective fighter and was
> palmed off on the Russians and the P-38 also had 4 .50 browning machine
> guns in it's nose. I even remember reading about a P-38 being fitted with
> a 75 mm single shot cannon that the pilot had to load between his legs.
>
> The P-51, -47, F4U, F6F, etc all used up to 8 .50 cal machine guns. As
> well as the B-17's, B-24's, etc on the Bomber force. I believe even the
> early B- 47's and B-52's had .50's in their tails and they weren't built
> until well after the war.
>
> Was the .50 cal the only thing we had available? The Japanese used 20 mm
> cannon on their fighters and I believe the ME-109 also had cannon on it?
>
Erik Shilling
<y.chi...@popmail.csuohio.edu> writes:
>
>
>> Several reasons. First, it was very reliable, more so than cannons
>amd had higher rate of fire. Muzzle velocity was simular. German,
Japanese, and British cannons were also very good, not much heavier
than 0.50 and had rate of fire very similar.
the weight of fire and was especially true of the 20 mm All mg's at
some point would stop firing if enough G's were pulled. Also the 20 mm
had less tolerance for G's than the fifties. It also depended upon the
amount of lift and distance require from the ammo box to the guns.
Erik Shilling
Emmanuel Gustin
news:jrc3-12089...@cx260707-a.mnchs1.ct.home.com...
> > I have a question for the group. Why did the US military use .50 cal
guns
> > on all of their fighters and bombers in World War II when there were 20
> > Millimeter machine cannon available.
There were several reasons. But first note that it is not entirely
fair to write "the US military": The USN had more attention for
20mm cannon than the USAAF, installed them in some of its
fighters and attack aircraft, and standardised on them after the
end of the war --- during the Korean war USN fighers carried
20mm cannon, USAF fighters .50s.
The USA had not developed its own 20mm cannon. The only
available 20mm weapon was the French-designed Hispano,
the same cannon as used by the British; but it was "not
invented here". There was a tendency to believe that because
the .50 was the best US gun, it had also to be the best gun
anywhere. And unlike other air forces, the USAAF was almost
obsessed with trajectory flatness and armour penetration; much
of the wartime development work was wasted on a series of
very high velocity .50 and .60 guns, which never were of any
use.
The Browning .50 was relatively cheap, abundant, and highly
standardized. For a force that was as large as the US WWII
military, and rapidly expanding, these were extremely important
advantages. Consider that the Germans used about 10 different
types of aircraft weaponry; the Japanese about 20! That not only
put a strain on the supply organisation, it also called for longer
training of armourers.
While the Browning .50 was relatively heavy and had an
unremarkable rate of fire, it had very good ballistic characteristics
and was extremely reliable. US fighters mostly had to deal with
enemy fighters and lightly built bombers; against those the .50
was sufficient. Another advantage of the .50 was that a larger
ammunition supply could be carried: Enough for 20 to 40
seconds of fire, while cannon-armed fighters were restricted to
10 to 20 seconds.
Finally, the USAAF and USN seem to have had some problems
to make the Hispano work reliable. In British service stoppages
were reduced to about 1 in 1500 rounds; in US service they remained
frequent. It is unclear to me why this happened. It may have been
a design problem with the gun mounts or the ammunition feed;
but it can also have been a training problem --- the Hispano needed
precise adjustment. The British considered that the American-made
cannon as good as their own...
> Third, it still hit pretty hard (compared to the .30-cal used in
> many European or Japanese fighters.
By mid-war, the .30 was evaluated as ineffective, and continued
to be used only where it could not easily be replaced (cowl guns,
the outboard guns on the Spitfire). The 20mm cannon was the
preferred weapon in all air forces except those of the USA.
> Fourth, it was smaller than a cannon, you could carry six or eight
> instead of 1 or 2.
Actually it was more a 2:3 ratio: The .50 weighed 30 kg, the
20mm cannon were in the range 25 kg to 50 kg. Although
structural strengthening of the aircraft to cope with the heavier
recoil added to the weight.
After 1942 most fighters carried 3 or 4 of the 20mm cannon,
or combined 2 cannon with some machineguns. The exception
were the small Soviet fighters.
> Finally, many of the cannons used were fairly short-ranged (due
> to short barrels), and the Browning .50 outranged them.
The 20mm cannon used by the Russians, the British and the
Japanese army had very similar muzzle velocities to the .50; the
ones with low muzzle velocities were the MG-FF installed in
German fighters before 1942 and the Type 99-1 and Type 99-2
used by the Japanese Navy.
See also
http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-fr.html
This has become a length site, but the most relevant parts are the gun
tables and the overview of some WWII fighters.
--
Emmanuel Gustin <gus...@NoSpam.uia.ac.be>
Home at University of Antwerp: http://nat-www.uia.ac.be/~gustin/
(Delete NoSpam. from my address. If you can't reach me, your host
may be on our spam filter list. Check http://www.uia.ac.be/cc/spam.html.)
Roy McMillion
various ammunition used during WWII. IF any one knows where such information
can be found. Please contact me.
Remove Anti-Spam measures to e-mail.
Indiana Joe <jr...@home.com> wrote in message
news:jrc3-12089...@cx260707-a.mnchs1.ct.home.com...
> In article <01bee4a9$642058c0$2550...@unit3ws01.comp.pge.com>, "Midnight
> Lurker" <em...@microsoft.com> wrote:
>
> >I have a question for the group. Why did the US military use .50 cal
guns
> >on all of their fighters and bombers in World War II when there were 20
> >Millimeter machine cannon available. I know that the P-39 had a .37 mm
> >cannon that fired through its propeller hub and that the P-38 had a 20 mm
> >cannon in its nose. But the P-39 was not an effective fighter and was
> >palmed off on the Russians and the P-38 also had 4 .50 browning machine
> >guns in it's nose. I even remember reading about a P-38 being fitted
with
> >a 75 mm single shot cannon that the pilot had to load between his legs.
>
> That was a design study, it never got to the prototype stage.
>
> >The P-51, -47, F4U, F6F, etc all used up to 8 .50 cal machine guns. As
> >well as the B-17's, B-24's, etc on the Bomber force. I believe even the
> >early B- 47's and B-52's had .50's in their tails and they weren't built
> >until well after the war.
> >
> >Was the .50 cal the only thing we had available? The Japanese used 20 mm
> >cannon on their fighters and I believe the ME-109 also had cannon on it?
>
> Several reasons. First, it was very reliable, more so than cannons or
> even other machine guns. Second, you could carry a lot of ammunition for
> it, you rarely worried about runing out. Third, it still hit pretty hard
> (compared to the .30-cal used in many European or Japanese fighters.
> Fourth, it was smaller than a cannon, you could carry six or eight instead
> of 1 or 2. Finally, many of the cannons used were fairly short-ranged (due
> to short barrels), and the Browning .50 outranged them.
>
Indiana Joe
eri...@ix.netcom.com(Erik Shilling) wrote:
>In <37B32441...@popmail.csuohio.edu> Yevgeniy Chizhikov
><y.chi...@popmail.csuohio.edu> writes:
>>
>>
>>> Several reasons. First, it was very reliable, more so than cannons
>or even other machine guns. They were lighter than Browning
>>amd had higher rate of fire. Muzzle velocity was simular. German,
>Japanese, and British cannons were also very good, not much heavier
>than 0.50 and had rate of fire very similar.
>>your have to take into consideration the fact that G forces reduced
>the weight of fire and was especially true of the 20 mm All mg's at
>some point would stop firing if enough G's were pulled. Also the 20 mm
>had less tolerance for G's than the fifties. It also depended upon the
>amount of lift and distance require from the ammo box to the guns.
>
>Erik Shilling
Careful there, you're putting my words in Yevgeniy's mouth. People might
think he's sensible. :-)
Actually, I can't tell who said what in that post, but I recognize some
of what I said in an earlier message in this thread. I hope you aren't
having newsreader problems.
D.L.
http://www.csd.uwo.ca/~pettypi/elevon/gustin_military/fgun.html
Roy McMillion <roym...@MicrosoftDOT.com> wrote in message
news:7p1frb$r...@news.dns.microsoft.com...
> > Several reasons. First, it was very reliable, more so than cannons or
> > even other machine guns. Second, you could carry a lot of ammunition for
> > it, you rarely worried about runing out. Third, it still hit pretty hard
> > (compared to the .30-cal used in many European or Japanese fighters.
> > Fourth, it was smaller than a cannon, you could carry six or eight
instead
> > of 1 or 2. Finally, many of the cannons used were fairly short-ranged
(due
> > to short barrels), and the Browning .50 outranged them.
> >
> > The M2 machine gun was a good weapon, don't discount it just because of
> > its size.
> >
Dave Eadsforth
<eri...@ix.netcom.com> writes
>In <37B32441...@popmail.csuohio.edu> Yevgeniy Chizhikov
><y.chi...@popmail.csuohio.edu> writes:
>>
>>
>>amd had higher rate of fire. Muzzle velocity was simular. German,
>Japanese, and British cannons were also very good, not much heavier
>than 0.50 and had rate of fire very similar.
>>your have to take into consideration the fact that G forces reduced
>the weight of fire and was especially true of the 20 mm All mg's at
>some point would stop firing if enough G's were pulled. Also the 20 mm
>had less tolerance for G's than the fifties. It also depended upon the
>amount of lift and distance require from the ammo box to the guns.
>
>Erik Shilling
The difficulty of keeping the guns firing through higher G forces was
solved to a great degree in British WWII fighters by the use of the
Molins Belt Feed Mechanism, which used a VERY strong wind-up spring
device to crank the ammo belt to the gun.
Molins went back to making cigarette handling machinery after the war.
Feel sure that there must have been some technology transfer involved
there...
Cheers,
Dave
--
Dave Eadsforth
Caius Marius
> Several reasons. First, it was very reliable, more so than cannons or
>it, you rarely worried about runing out. Third, it still hit pretty hard
>(compared to the .30-cal used in many European or Japanese fighters.
>Fourth, it was smaller than a cannon, you could carry six or eight instead
>of 1 or 2. Finally, many of the cannons used were fairly short-ranged (due
>to short barrels), and the Browning .50 outranged them.
...and now the U.S. gets criticized for using 20mm rather than 30mm. :-)
There's something to be said for standardization on reliable equipment. The
M-2 is STILL in use by the US military. Mr. Browning must have done something
right.
John - N8086N
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Emmanuel Gustin
news:7p4fsd$4au$1...@fir.prod.itd.earthlink.net...
> ...and now the U.S. gets criticized for using 20mm rather than
> 30mm. :-)
Well, the 20mm ammunition was adopted in the 1950s because
it was assumed that guns would be replaced by guided missiles
soon, so it was not worth the effort the develop the 30mm...
> Mr. Browning must have done something right.
Certainly. Among other things, the Browning .50 was also the basis
for one of the best 20mm cannon of the war -- the Japanese Ho-5.
The error was completely that of the armed forces. They insisted
on the development of .50 (and later .60) machineguns and 37mm
cannon, but ignored anything in between until the late 1930s, when
some foreign-designed cannon were hastily evaluated, but were
judged to be either unsatisfactory or very hard to get...
Perhaps this was for legalistic reasons, because it was considered
that 37mm was the smallest legal calibre for explosive ammunition
under the The Hague rules --- although these were dead letter.
(And besides, the USA did not hesitate to ignore its treaty
obligations if that was considered desirable.)
--
Emmanuel Gustin <gus...@NoSpam.uia.ac.be>
Fighter Guns Page: http://www.geocities.com/CapeCanaveral/Hangar/8217/
Julian Cosson
Caius Marius wrote in message <7p4fsd$4au$1...@fir.prod.itd.earthlink.net>...
>In article <jrc3-12089...@cx260707-a.mnchs1.ct.home.com>,
jr...@home.com (Indiana Joe) wrote:
>> Several reasons. First, it was very reliable, more so than cannons or
>>even other machine guns. Second, you could carry a lot of ammunition for
>>it, you rarely worried about runing out. Third, it still hit pretty hard
>>(compared to the .30-cal used in many European or Japanese fighters.
>>Fourth, it was smaller than a cannon, you could carry six or eight instead
>>of 1 or 2. Finally, many of the cannons used were fairly short-ranged (due
>>to short barrels), and the Browning .50 outranged them.
The US was never in a defensive position, virtually all the other countries
involved in WW2 had to shoot down bombers and thus required heavier weapons.
The 50 cal guns used by the US were great for use against other fighters and
"soft skinned" targets but not much use against bombers.
Julian Cosson
Rick Shay
aircraft during WWII? Perhaps because we simply thought it to be the best.
The BMG has several features that made it a relative winner (and arguable
still a champ today):
1) The physical Browning machine gun was small enough to fit inside the
wings of fighter aircraft with no bulges causing parasitic drag.
2) They had a good rate of fire without being too high. Bursts could be
controlled and ammo could be saved if necessary. The rate of fire also
allowed a higher concentration of projectiles in any given moment (when the
projectile stream was coincided with the target, for instance) than a 20 mm
or 30mm cannon of the time would allow.
3) The .50 caliber projectile was of sufficient diameter and weight to
allow several effective types of projectiles, i.e. Armor Piercing, Tracer,
Incendiary, etc. (We experimented with .50 caliber explosive rounds a little
later, but they proved to be too fragile (read dangerous) and not too
effective. A bad combination. I can remember seeing a picture in a book on
the F-86 Saber Jet of Korean War vintage that showed it machine gun ammo bay
having blown up with some of this experimental ammunition loaded aboard.
4) The velocity was high enough to have a much flatter trajectory that
cannon rounds at the time (effective zero'd in distances were relatively
larger.)
Conversly, The aircraft cannons at the time, be they Russian, American,
British, or German, had several negative features, (all factors being
paramount UNLESS the round actually impacted the target):
1) They had a SLOW rate of fire. There was no "stream" of projectiles in a
fast moving air battle.
2) On-board ammo was restricted to a relatively small number of rounds
because of size and weight considerations.
3) The location of the actual canon was often external to the wings (either
built internally to the fuselage (takign up valuable space,) or mounted
externally in drag-inducing blisters or pods.)
4) They were LARGE, heavy mechanisms.
5) They were all of a low velocity, making effective placing of the shots
more difficult.
You spoke of .50 BMG's being also mounted in the early jets. A friend has an
interesting round in his collection, a .60 Caliber machine guin round,
considerable larger in case capacity, etc. It looks very effective but I do
not know what aircraft mounted guns to fire it. Does anyone know?
Hope this helps,
Rick A. Shay
Midnight Lurker <em...@microsoft.com> wrote in message
news:01bee4a9$642058c0$2550...@unit3ws01.comp.pge.com...
> I have a question for the group. Why did the US military use .50 cal guns
> on all of their fighters and bombers in World War II when there were 20
> Millimeter machine cannon available. I know that the P-39 had a .37 mm
> cannon that fired through its propeller hub and that the P-38 had a 20 mm
> cannon in its nose. But the P-39 was not an effective fighter and was
> palmed off on the Russians and the P-38 also had 4 .50 browning machine
> guns in it's nose. I even remember reading about a P-38 being fitted with
> a 75 mm single shot cannon that the pilot had to load between his legs.
>
> The P-51, -47, F4U, F6F, etc all used up to 8 .50 cal machine guns. As
> well as the B-17's, B-24's, etc on the Bomber force. I believe even the
> early B- 47's and B-52's had .50's in their tails and they weren't built
> until well after the war.
>
> Was the .50 cal the only thing we had available? The Japanese used 20 mm
> cannon on their fighters and I believe the ME-109 also had cannon on it?
>
Yama
Argh...people should _really_ read previous replies.
> <snip>
> Conversly, The aircraft cannons at the time, be they Russian, American,
> British, or German, had several negative features, (all factors being
> paramount UNLESS the round actually impacted the target):
>
> 1) They had a SLOW rate of fire. There was no "stream" of projectiles in a
> fast moving air battle.
True only with some early war cannons, or larger (30+mm). ShVAK,
Hispano, MG151/20 etc. had rate of fires equal to contemporary heavy
mg's.
> 3) The location of the actual canon was often external to the wings (either
> built internally to the fuselage (takign up valuable space,) or mounted
> externally in drag-inducing blisters or pods.)
20mm cannons were put into wings of many fighters internally without
much trouble (Tempest/Typhoon, FW190, Hurricane, Corsair etc). I
fail to see how space in the forward fuselage was more valuable than
space in the wings. Best place for a gun was through propeller shaft
(like in Bf 109) but not all engines allowed this.
> 4) They were LARGE, heavy mechanisms.
Depending - Soviet B-20 was _lighter_ than M2.
> 5) They were all of a low velocity, making effective placing of the shots
> more difficult.
Not true. Most cannons (mentioned above) had muzzle velocities equal
or better than .50cal.
Keith Willshaw
Rick Shay <rick...@gr.hp.com> wrote in message
news:7p9v8u$6i8$1...@hpbs1500.boi.hp.com...
>
> Conversly, The aircraft cannons at the time, be they Russian, American,
> British, or German, had several negative features, (all factors being
> paramount UNLESS the round actually impacted the target):
>
> 1) They had a SLOW rate of fire. There was no "stream" of projectiles in
a
> fast moving air battle.
True of early cannnons which is why RAF fighters of the 1940 used
6 machine Guns but later guns had comparable ROF
> 2) On-board ammo was restricted to a relatively small number of rounds
> because of size and weight considerations.
> 3) The location of the actual canon was often external to the wings
(either
> built internally to the fuselage (takign up valuable space,) or mounted
> externally in drag-inducing blisters or pods.)
> 4) They were LARGE, heavy mechanisms.
Franly if you can mount 4 Cannon in the Extremely Thin
Elliptical wing of Spitfire I can't really see this being
a problem
The simplest answer is the .50 was good enough to
soldier on with and it was available in LARGE numbers
when needed
The .30 MG was just to small to do the damage required
and so was replaced faster.
Keith
Keith Willshaw
Keith Willshaw <10057...@compuserve.com> wrote in message
news:7pbm3i$g58$1...@ssauraaa-i-1.production.compuserve.com...
>
> Rick Shay <rick...@gr.hp.com> wrote in message
> news:7p9v8u$6i8$1...@hpbs1500.boi.hp.com...
> >
> > Conversly, The aircraft cannons at the time, be they Russian, American,
> > British, or German, had several negative features, (all factors being
> > paramount UNLESS the round actually impacted the target):
> >
> > 1) They had a SLOW rate of fire. There was no "stream" of projectiles
in
> a
> > fast moving air battle.
>
> True of early cannnons which is why RAF fighters of the 1940 used
> 6 machine Guns but later guns had comparable ROF
>
Correction 8 .303 MG's
Keith
Paul J. Adam
<rick...@gr.hp.com> writes
>You spoke of .50 BMG's being also mounted in the early jets. A friend has an
>interesting round in his collection, a .60 Caliber machine guin round,
>considerable larger in case capacity, etc. It looks very effective but I do
>not know what aircraft mounted guns to fire it. Does anyone know?
It was developed, proved less than wholly satisfactory, and was never
fielded. It had an extremely high muzzle velocity and rate of fire, but
couldn't fire effective explosive projectiles.
Development began in 1939 , the first prototype appeared in late
1941, and a production contract was placed with Rock Island Arsenal
in 1943: however, the performance of 20mm cannon (a licence-
produced Hispano-Suiza) also coming into production was good
enough that it was used in place of the .60cal.
--
There are four kinds of homicide: felonious, excusable, justifiable and
praiseworthy...
Paul J. Adam pa...@jrwlynch.demon.co.uk
Emmanuel Gustin
news:7p9v8u$6i8$1...@hpbs1500.boi.hp.com...
> The BMG has several features that made it a relative winner (and arguable
> still a champ today):
>
> 1) The physical Browning machine gun was small enough to fit inside the
> wings of fighter aircraft with no bulges causing parasitic drag.
Depends on the installation. Remember, the .303 Browning
required bulges in the Spitfire :-). However, throughout the war
20mm cannon were installed in wings without many problems.
Actually the Browning .50 was a rather big and heavy weapon
for its calibre; the 20mm Hispano was long but slim, and the Soviet
Beresin B-20 was lighter than the Browning. The reason cannon
often required bulges early in the war was that they were
drum-fed. The bulky drums were later replaced by belts.
> 2) They had a good rate of fire without being too high.
I wonder what you would describe as "too high". The USA
actually made a serious effort to boost the .50 from 850rpm
to 1200rpm. This Browning M3 was too late for WWII, but
saw service in Korea.
> Conversly, The aircraft cannons at the time, be they Russian, American,
> British, or German, had several negative features, (all factors being
> paramount UNLESS the round actually impacted the target):
> 1) They had a SLOW rate of fire. There was no "stream" of projectiles
> in a fast moving air battle.
Actually the rates of fire of most 20mm cannon ranged from 600 up to
850 rpm, which does compare rather well with the 650 to 850rpm
of the Browning .50 (it was modified during the war to increase its rate
of fire.) There were a few "slow" ones, such as the German MG-FF
and the Japanese Navy Type 99-1 and 99-2, but even these managed
470 to 520rpm.
> 2) On-board ammo was restricted to a relatively small number of rounds
> because of size and weight considerations.
True. Generally 200 rounds or less, often around 120, early in the
war only 60. Compared to sometimes as many as 400 for the .50.
The 20mm projectiles were between two and three times heavier
than the .50s. On the other hand, they were much more effective
because they could carry larger explosive and incendiary loads, so
pilots could fire shorter bursts.
> 3) The location of the actual canon was often external to the wings
> (eitherbuilt internally to the fuselage (takign up valuable space,) or
> mounted externally in drag-inducing blisters or pods.)
Externally-mounted 20mm cannon were very rare. The only fighter
on which they were common was the Bf 109G. (The .50 was also
externally mounted at times, for example on the P-63.) It was
perfectly well possible to install the 20mm cannon in the wings,
as numerous examples show (Fw 190, Spitfire, Tempest, A6M, ...).
Fuselage installations were mainly popular with the Soviets, although
the Germans used them on the Bf 109. The Soviet designers seem to
have preferred them becuase (1) they concentrated fire, (2) The
concentration of the weight around the c.g. was beneficial to
manoeuverability; (3) wing-mounted guns are less accurate because
the wing inevitably twists a bit under loads.
> 4) They were LARGE, heavy mechanisms.
Depends. The Browning .50 weighed about 30kg. The 20mm cannon
ranged from 50kg (Hispano Mk.II) to a mere 25kg (Berezin B-20).
The US Navy judged that the 20mm Hispano was worth three .50s,
or 2.5 at long range; even at the latter value the 20mm cannon gives
heavier firepower for less weight.
> 5) They were all of a low velocity, making effective placing of the shots
> more difficult.
Definitely NOT true. British and Soviet 20mm cannon had muzzle velocities
very close (difference 10 m/sec) to that of the .50; the German MG 151/20
was a bit lower. But the only real low-velocity cannon were the MG-FF/M
and Type 99-1, used early in the war by the Germans and the Japanese
Navy, respectively.
> A friend has an interesting round in his collection, a .60 Caliber machine
> guin round, considerable larger in case capacity, etc. It looks very
effective
> but I do not know what aircraft mounted guns to fire it. Does anyone know?
Several US .60 guns were developed during WWII. One of them was
the T17, firing .60 rounds with a case length of 114 millimiter. The T17
was a development of the perfectly good German 15mm Mauser MG 151
(courtesy of the RAF). After many changes, several hundred T17 were
built which were promptly put into storage...
During WWII the USA wasted an enormous effort on the development
of .60 guns. This is the most important reason for the continued use of
the .50: The USAAF blunty ignored that everyone else (even the USN)
was gradually switching to 20mm cannon, and spent much development
money on better .50s and .60s... What could have been done was
demonstrated by the Japanese Army, which developed an excellent
20mm version of the Browning .50...
For an even longer discussion, see the website in my signature.
luminou...@hotmail.com
> I have a question for the group. Why did the US military use .50 cal guns
> on all of their fighters and bombers in World War II when there were 20
> Millimeter machine cannon available. I know that the P-39 had a .37 mm
> cannon that fired through its propeller hub and that the P-38 had a 20 mm
> cannon in its nose. But the P-39 was not an effective fighter and was
> palmed off on the Russians and the P-38 also had 4 .50 browning machine
> guns in it's nose. I even remember reading about a P-38 being fitted with
> a 75 mm single shot cannon that the pilot had to load between his legs.
>
> The P-51, -47, F4U, F6F, etc all used up to 8 .50 cal machine guns. As
> well as the B-17's, B-24's, etc on the Bomber force. I believe even the
> early B- 47's and B-52's had .50's in their tails and they weren't built
> until well after the war.
>
> Was the .50 cal the only thing we had available? The Japanese used 20 mm
> cannon on their fighters and I believe the ME-109 also had cannon on it?
>
> Thanks in advance.
>
> Larry Ries
mmcla...@gmail.com
Diogenes
>Go tell the Russians and the hundreds of Nazis they shot down that the P39 wasn't an effective fighter. Just because the US and UK didn't want to figure out how to make it work didn't mean it wasn't a good airplane.
Lt. Park flew the P39 in combat and named his plane Nanette. He swears
that "she" had a personality and could be sweet, cooperative, nasty or
bitchy depending upon her mood. By the time you finish the book he
will have you convinced that Nanette was a living entitiy.
----
Diogenes
The wars are long, the peace is frail
The madmen come again . . . .