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/