Best dogfight gun?

"Tony Williams" wrote in message
m...
The ideal gun for aerial combat will of course combine the best of all
worlds: a high rate of fire, instantly achieved; a high muzzle
velocity to minimise flight time; and projectiles large enough to
inflict serious damage with each hit (requiring a calibre in the 25 -
30 mm range). The optimum weapon among those currently developed may
well be the new GIAT 30M791 revolver, although its weight means that
two GSh 301s (or a GSh-30) could be carried instead, with a higher
rate of fire. If the Russian guns' 30 x 165 ammunition were loaded
with lighter projectiles for a higher muzzle velocity, its aerial
combat capabilities would be improved, at the cost of some loss of
ground attack effectiveness."

Is there more behind the "requiring a calibre in the 25-30 mm range"
than hand-waving to dismiss 20mm guns? Granted, bigger is better,
but why isn't 40mm required or 20mm enough?

"John Keeney" wrote in message
...

"Tony Williams" wrote in message
m...
The ideal gun for aerial combat will of course combine the best of all
worlds: a high rate of fire, instantly achieved; a high muzzle
velocity to minimise flight time; and projectiles large enough to
inflict serious damage with each hit (requiring a calibre in the 25 -
30 mm range). The optimum weapon among those currently developed may
well be the new GIAT 30M791 revolver, although its weight means that
two GSh 301s (or a GSh-30) could be carried instead, with a higher
rate of fire. If the Russian guns' 30 x 165 ammunition were loaded
with lighter projectiles for a higher muzzle velocity, its aerial
combat capabilities would be improved, at the cost of some loss of
ground attack effectiveness."

Is there more behind the "requiring a calibre in the 25-30 mm range"
than hand-waving to dismiss 20mm guns? Granted, bigger is better,
but why isn't 40mm required or 20mm enough?

One reason is range but that's a mug's game, trying to compete with SRAAMs.
The other reason, lethality, is driven by the fact that fighters are a lot
tougher targets now than they were fifty years ago. In a progression of
lethality, during WWII, .50cal machine guns were adequately lethal against
fighter sized targets but not against bombers. With the advent of jet
propulsion, increased air speed required stronger structure and fighters got
physically tougher, so 20mm was optimum against fighters in the late forties
and early fifties. Supersonic fighters are tougher still, mostly because of
increase design dynamic pressure but also because they are stressed for
larger loads and higher g-loads, so the thought is that 20mm rounds have
inadequate Pk (given a hit).

Of course, gun installations are questionable now because the SRAAMs have
gotten so good and because guns in general pose a significant cost in
reliability (the firing forces become the design environment for all the
electronics in the vicinity) and a significant maintenance burden.

(Tony Williams) wrote in
m:

Greg Hennessy wrote in message
. ..
On Fri, 05 Dec 2003 07:45:39 GMT, Chad Irby wrote:


Whats the avarage gun burst time in a dogfight...

Whatever it is, you're going to have to hold the trigger down for
over three times that to get the same amount of fire downrange.

Given the that the designer of the mig-29 is on record as saying that
he should have halved the number of rounds carried for its gsh-30L.
Tony Williams has a table on his website which details why a single
barrelled cannon will get there 1st with the mostest when compared to
a gatling.

This is from 'Flying Guns: the Modern Era' by Emmanuel Gustin and
myself, due to be published in March next year:

"There are three competing philosophies when it comes to gun design
for fighter aircraft. One is the US rotary; fast-firing but (to date)
only 20 mm in calibre, and a very bulky system. The second is the West
European preference for a 27 – 30 mm revolver cannon; no lighter,
but slimmer and hard-hitting. The third is represented by the Russian
GSh 301; a minimalist gun but with an equally hard-hitting
performance. The twin-barrel GSh-30 also deserves mention, even though
it has not been used in fighter aircraft. It weighs about the same as
the western guns at 105 kg, but fires powerful 30 mm ammunition at up
to 3,000 rpm.

The merits of the 27 mm BK 27 revolver as opposed to the M61A1 can be
clearly demonstrated. In the first 0.5 seconds of firing, the M61
fires 18 rounds massing 1.8 kg in total weight of projectiles, the BK
27 fires 14 rounds weighing 3.7 kg. In the first full second, the M61
fires 68 rounds weighing 6.9 kg, the BK 27 fires 28 rounds weighing
7.4 kg. In weight of fire, as well as the destructiveness of the
individual projectiles, the Mauser clearly has an advantage, albeit
one that the faster-accelerating M61A2 reduces somewhat. This is
significant in that dogfights frequently permit only the briefest of
firing opportunities, and although a skilled pilot anticipating a
firing opportunity can 'spin up' a rotary in advance, such notice
cannot always be guaranteed.

The Mauser projectiles are also relatively heavier, resulting in a
sectional density (SD) of .507 compared to .363 for the 20 mm, which
means they will retain their initial velocity out to a greater range.
The 30 mm GSh-301 offers similar performance to the BK 27 with about
half the weight. On paper, this is an impressive fighter gun, although
its maintenance requirements have been criticised. The choice of a
heavy projectile (with an SD of .616) at a moderate velocity for the
Russian 30 mm guns implies that ground attack has a higher priority
than aerial combat in Russian thinking.

The ideal gun for aerial combat will of course combine the best of all
worlds: a high rate of fire, instantly achieved; a high muzzle
velocity to minimise flight time; and projectiles large enough to
inflict serious damage with each hit (requiring a calibre in the 25
– 30 mm range). The optimum weapon among those currently developed
may well be the new GIAT 30M791 revolver, although its weight means
that two GSh 301s (or a GSh-30) could be carried instead, with a
higher rate of fire. If the Russian guns' 30 x 165 ammunition were
loaded with lighter projectiles for a higher muzzle velocity, its
aerial combat capabilities would be improved, at the cost of some loss
of ground attack effectiveness."

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


Careful! don't praise the GIAT gun--Al Minard is going to **** his pants
again.

This parsing of the snap-shot situation concluding a half second
advantage in fire weight - even a full second - is rather disingenuous
in that a skilled pilot will see the possibility of a snap shot
developing and be already firing before the non-tracked target passes
through the zone of fire. I well remember that gun camera film of
Korean War F86 pilot Major Pete Fernandez' ninety degree shot on a MiG
15 - he was firing before the MiG entered the pcture - hits plastered
the MiG and it went out of the frame smoking badly. IN WW2 one of the
'experten' jumped Sailor Malan - Malan broke into his attacker and
hosed him on a quartering head-on shot. The attacker was wounded badly
and had to break for home. His name doesn't come to me at the moment.
I maintain the M61 can hold its own in any situation. Situation
awareness is the key. Without that the impulsive squeeze of the
trigger as an aircraft passes swiftly in front of you is generally
futile as the rounds will pass behind him.
Walt BJ