Has there ever been an off-center gun?

"Bob Martin" wrote:

Of course, I
also seem to recall that the shell basically traces a straight line
from barrel to "effective range", and doesn't need drop factored in.

Eh?... surely you're not saying that the rounds don't drop in
flight?...I hope?...


Well, I know the firing barrel is centered laterally, but I think the gun
itself may be angled down a couple degrees (though still passing through the
center of gravity of the aircraft, so as to not produce any pitching
moment), though probably not more than 2 or 3. This would help with gun
tracking and make strafing runs a little safer.

As far as the "straight line" from the barrel... the muzzle velocity of the
GAU-8/A is such that, although the bullets do drop in flight (to not do so
would either imply lift being generated, or laws of physics being violated),
the drop is considered negligible, and therefore the gunsight is a simple
fixed reticle in the HUD.

For example... at 4000 feet, the bullets will only drop about 10
feet--random dispersion will be greater than that.


But that puts the centre of the dispersion pattern ~ten feet
below the aim point at that range doesn't it?
--

-Gord.

"B2431" wrote in message
...

It amazes me I can't remember 24 hours ago yet I can remember 35 years
ago.

Yet the rest of us are amazed when you make up things from 35 years ago,
Dan.

For example... at 4000 feet, the bullets will only drop about 10
feet--random dispersion will be greater than that.


But that puts the centre of the dispersion pattern ~ten feet
below the aim point at that range doesn't it?

Yeah, but that's only about a sixth of a degree of arc...

also, a tank is what, 6-8 feet tall at least? Ten feet at that range is
very little to be concerned about... anyways, the point being that gravity
drop is less of a factor with the GAU-8 than with other guns.

(OXMORON1) wrote:

The mail/supplies in the bucket trick goes back farther than that. IIRC the
"bucket trick" was the inspiration for the AC-47 development for holding the
fire on the target in a steep banked turn.

In addition to the Amazon, the technique was used by missionaries in Borneo,
both sometime in the late twenties or early thirties.

Oxmoron1
Don't ask me where I read it,but it was a long time ago.

As the legend goes, the missionaries discovered that by squaring
their groundspeed and dividing that figure by 15, they would arrive at
the proper "pivotal altitude" from which to fly circles allowing them
to lower a bucket of medicine and supplies to people on the ground.
Nowadays the maneuver is called Eights On Pylons.

"Cub Driver" wrote in message
...

This is wonderful. Can either of you or anybody point me to more
information about this service?

I realize there are only 12 issues of Geographic a year, but it would
help if I could narrow it down.

I've read about the same technique being used in Oz for back country
mail.

From: "Tarver Engineering"
Date: 12/8/2003 7:31 PM Central Standard Time
Message-id:


"B2431" wrote in message
...

It amazes me I can't remember 24 hours ago yet I can remember 35 years
ago.

Yet the rest of us are amazed when you make up things from 35 years ago,
Dan.

Tarver, I cited my source which is something you have never done.

Until you have something constructive to say go chew on a bowlful of rusty
double edged razorblades at let us grownups talk.

Dan, U. S. Air Force, retired

On 08 Dec 2003 23:23:12 GMT, (OXMORON1) wrote:

The mail/supplies in the bucket trick goes back farther than that. IIRC the
"bucket trick" was the inspiration for the AC-47 development for holding the
fire on the target in a steep banked turn.

In addition to the Amazon, the technique was used by missionaries in Borneo,
both sometime in the late twenties or early thirties.


There's at least one on-line ref to a basket of eggs being delivered
this way in 1939, so it was probably done quite a few years before
that. I would think the technique grew out of all of the multiple
experimentations in the 1920s for dropping off air mail without
landing.

John Hairell )

"Bob Martin" wrote in message ...
For example... at 4000 feet, the bullets will only drop about 10
feet--random dispersion will be greater than that.


But that puts the centre of the dispersion pattern ~ten feet
below the aim point at that range doesn't it?

Yeah, but that's only about a sixth of a degree of arc...

also, a tank is what, 6-8 feet tall at least? Ten feet at that range is
very little to be concerned about... anyways, the point being that gravity
drop is less of a factor with the GAU-8 than with other guns.

Right, that was basically it. Operationally speaking, at ranges where
the A-10 intiates/presses an attack, the GAU-8 fires a straight shot.
I also remember a graphic detailing muzzle velocity of the 23mm round
from the ZSU versus from a GAU-8, and it showed that if a Hog and a
ZSU fired accurate rounds at each other at the same exact time, the
ZSU died first and the Hog could (conceivably) jink before the 23mm
arrived. Pretty neat stuff, if somewhat idealized.

"Bob Martin" wrote:

For example... at 4000 feet, the bullets will only drop about 10
feet--random dispersion will be greater than that.


But that puts the centre of the dispersion pattern ~ten feet
below the aim point at that range doesn't it?

Yeah, but that's only about a sixth of a degree of arc...

also, a tank is what, 6-8 feet tall at least? Ten feet at that range is
very little to be concerned about... anyways, the point being that gravity
drop is less of a factor with the GAU-8 than with other guns.


I see...that's interesting...how do they do that? (your last
sentence I mean)

-Gord.

"I'm trying to get as old as I can,
and it must be working 'cause I'm
the oldest now that I've ever been"

Gord Beaman wrote in message
...
"Bob Martin" wrote:

For example... at 4000 feet, the bullets will only drop about 10
feet--random dispersion will be greater than that.


But that puts the centre of the dispersion pattern ~ten feet
below the aim point at that range doesn't it?

Yeah, but that's only about a sixth of a degree of arc...

also, a tank is what, 6-8 feet tall at least? Ten feet at that range is
very little to be concerned about... anyways, the point being that
gravity
drop is less of a factor with the GAU-8 than with other guns.


I see...that's interesting...how do they do that? (your last
sentence I mean)

That's what I've been trying to explain... the bullets from the GAU-8 go
faster and therefore drop less for a given range than do bullets from other
guns. The smaller the drop, the easier it is to compensate for. In the
case of the A-10, the drop is so small that, for practical purposes, the
bullets go in a straight line.