The perfectly straight line issue is different than whether the bombs fall realistically or not, because in the game, every aerodynamic shape and effect is "perfect".
If you drop 2 wingless spitfires from 20k, one after another, in the game they ought to hit exactly one after another because the aerodynamic forces applied to the planes is consistently applied. With bombs, the modelling is also consistently applied.
To add dispersion, what we need is for the bomb to "wobble" (hehe) randomly as it exits the bomb bay, simulating it passing through the turbulent air surrounding the bomber. The amount of wobble could be estimated by looking at some of those bomb bay films taken during WWII... In any case, add the slight initial wobble to the bomb's vector immediately as it leaves the aircraft, and bingo! The higher you are, the farther the bomb will stray from a perfect flight path because it started with a very very small difference in heading or dive angle. This would be similiar to what might happen if you drop a string now while pumping the stick, rudders, and throttle all at once during the drop. Try that out, and see if you get the dispersion you want

One other way HTC could add realism to the bomb drop, would be to apply the wind vectors to the bombs as they pass through the wind layers. That would definately affect bomb accuracy

Of course, game bomber pilots would scream bloody hell, because suddenly the norden wouldn't be worth crap unless you actually used math and wind estimates like real life navigators and bombadiers, and nobody would ever take the time to do that because it's not easy.
I still like the little wobble idea... Just a very small adjustment to the bomb's trajectory as it exits the bomb bay. The lower you are at the drop, the less this adjustment would have to the bomb's accuracy. Think of it as dispersion for bombs

Someone pass this along to HT and Pyro if ya like it...
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eagl <squealing Pigs> BYA
Oink Oink To War!!!