I was able to get a missile with 10 speed to hit, though it did miss a lot more than it should have. Much earlier, I had created a modified version of the frigate anti-fighter missile with a speed of 1, a turn speed of 10 and a tracking speed of 10. Even though it has slightly less tracking speed than the normal anti-fighter missile, it still has a better chance to hit because it travels twice as fast and can make much sharper turns. To test your idea I just raised my modified missile’s speed to 10. It did hit a lot less. So I would say that yes past a certain speed missiles do get less accurate. But it’s probably a very high speed. For example, the Scavenger Racktenorgel has a tracking speed of 0.60 and a missile speed of 2. Against slow cruisers it hits very consistently despite its high speed.
I would say that turn speed, rather than accuracy, is most closely linked to missile speed. For example, my modified anti-fighter missile can fly circles around a frigate if I gave it enough fuel. However, when I raised its speed to 2, its turning radius doubled. Because it was twice as fast it now had to fly twice as far to turn the same amount. And, conversely, if I lowered the speed .33 its turning radius would be 1/3 of what it was originally.
Here is the code for my modified frigate anti-fighter missile: (with its speed raised to 10)
[config]
unlockcost = 0
lockable = 0
armour_penetration = 17
category = “WEAPONS”
classname = “SIM_MissileModule”
cost = 100
crew_required = 10
damage = 20
description = “These new, more powerful missiles were developed to counter those pesky fighters packing shield generators.”
fire_interval = 1000
flareuvid = 0
fuel = 700
guiname = “Enhanced Anti-Fighter Missiles”
has_decoys = 0
has_flare = 1
hitpoints = 40
icon = turret
max_range = 600
min_range = 60
missilelength = 4.0
missilespeed = 10.0
missilewidth = 2.0
name = “frigate antifighter missile II”
powerconsumed = 10.0
shield_penetration = 0
size = “FRIGATE”
slot_type = TURRET
sound = data/sounds/missile_launch.ogg
soundvolume = 1.00
trail_fade_time = 250
tracking_speed = 10.0
turnspeed = 10.0
turret_sprite = “turret_miss_v4”
turretsize = 12.0
warhead = EXPLOSIVE
weight = 50
[dataitems]
0 = cost,DECIMAL
1 = weight,DECIMAL
2 = hitpoints,DECIMAL
3 = powerconsumed,DECIMAL
4 = max_range,DECIMAL
5 = damage,DECIMAL
6 = fire_interval,INTEGER
7 = tracking_speed,DECIMAL
8 = shield_penetration,DECIMAL
9 = armour_penetration,DECIMAL
10 = fuel,DECIMAL
11 = missilespeed,DECIMAL
12 = crew_required,INTEGER
13 = min_range,DECIMAL
14 = has_decoys,BOOL