Thanks for the replies. I suppose I might have misrecollected.
I see that the
details on the official wiki paint a clearer picture. A smart missile doesn't self destruct after 5km but it does around 7.5 which will seem similar to the player. Meanwhile, heavy dumbfire can fly a whopping 24! I know what I am bringing to my next station turret run. (Although I think the last time I did that the shields rebuffed me.)
That said, I probably would mod them to have a considerably longer lifetime because dodging missiles is so easy the AI does it by accident most of the time, you can shoot them down, and most of them are easily foiled by countermeasures. Considering everyone can hold a rather limited number of missiles, I think they are precious commodities that have more than enough counterbalances without giving them a range barely longer than most M-sized ships.
But I could keep the low lock on range because of engine limitations and also so people can still enjoy gun range combat, despite the realism inconsistencies. Maybe the ECM is just really good in the X universe so that's just as good as lock on ranges get.
What I would really like to do is be able to load up a Destroyer with swarms or smart missiles and they would be able to put up a persistent stream of relocking missiles that would prove repellent to fighters for a while. But at the moment what happens is they blow through their missile stock fairly quickly and most of the missiles will self destruct en route to their targets after missing once.
On top of that a light missile hits with the power of an aggressive spitwad, and heavy missiles are too slow to catch many targets when fired from a destroyer, so between misses and weak hits you can expect a destroyer to blow through about 200 missiles to bring down a handful of Xenon M. Granted, they'll do it faster than a flak loadout, but for a very limited duration. Efficiency works out better if you put them on a couple of heavy hardpoints instead because they dole them out slower so the missile interception timing is less likely to be awful.
So overall it feels like missiles have been repeatedly nerfed far below where they should be. But if they actually had enough fuel range to leverage their self guidance then they would have a niche.
However, missiles do have another niche: they don't compete with other weapons for heat. So, for forward mounted weapon arrays, you can up your sustained damage by sprinkling a few launchers in there. E.g. on a PAR Perseus instead of two chainguns try a chaingun and a missile launcher. A shame Corvettes have such abysmal missile capacity. Also not relevant for capital ships where your turrets keep their heat to themselves, of course.
