I'm certainly no railgun master, but I've had a lot more success with them by getting used to their timing and hitting the trigger when "I will be on target when the charge cycle completes" rather than "get on target, hit trigger, stay on target til it fires" and it seems to me that the NPC behavior is designed to mimic this. Certainly, if I have changed my ships vector during the charge time before they fire they seem to be much more likely to miss. On the other hand, if I maintain a constant vector for longer than a rails charge time they are very likely to nail me... This isn't instafiring, it's just that being computer programs they are VERY good at predicting the right moment to press the trigger so that the gun fires just as the reticle crosses the target.
i don't know... I been doing some pretty erratic moves in a condor (fighter) and they get a hit , To the point that, if they where tracking me, or predicting where i may be, it would seem impossible, as they can't maneuver as well.
Still, i cant be sure, we don't know how it works, so you could be right
A beam laser is a weapon that needs to stay on target. A rail gun does not: You just need to be on-target when they fire. There's a big difference.
And yes: computer are aimbots. By definition. Although given the limited ammunition, I don't fire rails unless I have an 80%+ chance of hitting, either.
i know this

maybe my wording was wrong
yes, they only need to be on target when the shot is fired... staying on target meant being in the right location when it fires... this is a skill. Yes you dont have to be on the target all the time like with beam laser.
I fly fighters a lot (my main ship for combat,most fun), and the accuracy NPC seem to have to track me, and get on target at the point of firing seem a bit to good... to the point that if they had chosen to charge up their weapons, by the time they fire, there is no way the ship could have maneuver to the correct position. (unless i'm getting it wrong because of the heat of battle, normally more that one ship)
Thus, why i think NPC have a cool down per shot and not a charge up.