"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.