A- I suspect internet lag is more at fault than anything. An aircraft moving at 300MPH is moving at around 440 feet per second. I have no idea how much time actually passes before two players' computers receive and translate information through the internet, but if it took 1/10th of a second, each plane (assuming a 300 MPH speed) would travel about 44 feet. That could be seen as significant.
"or unless his guns are canted upwards with a built in lead - which they are not in Aces High except for gunners poistions."
B- There may be some merit to the above as well. In effect the guns on an airplane are canted upwards. Three times, even...
Having never sat in an aircraft and fired its guns, I'm unable to tell you how much effect it has, but I know a lot about shooting, and some of the basics of aircraft design and flight.
When a gun fires a bullet, the bullet begins falling the instant it exits the barrel (gravity)(unless fired vertically). In all firearms, this is compensated for by canting the barrel upwards. A rifle sighted in at 200 yards is not shooting flat. The scope (or sights) is/are pointed directly at the target (line of sight) but the barrel is tilted slightly upwards. A gun barrel sighted in at 200 or 300 yards is tilted upward more than a gun sighted in at 50 yards. A gun sighted in at 200 yards will shoot "high" at 100 because of the bullets arched trajectory. Throw a ball to someone across the room. It is impossible to throw it "flat", it flies in an arch, just as a bullet does. (It's a lot harder to see the bullet fly, though).
When you sit in an airplane, guns mounted in the wings are under the pilots eye level (by several feet). If the guns are sighted in at 300 yrds (convergence) the bullet starts out below the pilots line of sight, angled upwards. The bullets hit the target at the convergence (sighted in) distance. Further away than that they will hit low. But before they hit the 300 yrd target, the bullets have actually traveled at an upward angle, in an arched trajectory, and passed above the pilots line of sight, so that as they fall through 300 yrds they are on target. The further below the pilots eye level that the guns are mounted, the more pronounced the angle would be. Picture this from the side, and you'll see there is actually a pretty good angle involved.
Lastly, the wing itself on an airplane is traveling at a positive angle to the airflow. In effect, the wing itself is canted nose-up slightly (forced to do so by the horizontal stabilizer and the elevator). In level flight at high speed, we're not talking about a lot, but as speed lowers, the angle has to increase to counter gravity. In turning maneuvers, the angle is increased too. When the angle increases too far relative to the airflow, the wing stalls. The wing doesn't stall instantaneously, but rather builds as the angle relative to the slipstream builds.
Obviously, convergence settings (sighting in) were handled on the ground with the aircraft stationary. So bullets set for a 300 yard convergence will only hit a target 300 yards away if the plane is level. Pointing the nose up or down alters (flattens) the trajectory, so bullets will still "cross" at 300 yards, but will hit high. It doesn't matter whether the nose is pointed up or down, the bullets will still hit high. You can visualize that by imagining a gun barrel firing straight up, or straight down. The flight path of the bullet is verticle (assuming no wind). No arched trajectory. The arched trajectory is at its maximum when the bullet is fired "level".
Make things more complicated by remembering that even if the nose of the plane is verticle, the gun barrels are now pointed "past" verticle, due to sighting in and wing incidence. Make it even more complicated by throwing in things like a moving firing platform (the airplane in flight), trying to hit a moving target, and throwing G-forces and "non-level" flying etc. into the mix. Tilt the plane 45 degrees left or right (as viewed from the rear), and imagine where the bullets will go. Wow!
Is it any wonder we miss so much, trying to shoot those big ol' planes down??? If only I could get my shooting in AH to be as accurate as with my flintlock rifle!
I don't know how much each of these factors truly affects how we see things in the game. My guess is lag is the thing really to blame, I just thought I'd throw the others in as "food for thought".
MtnMan