I've been playing around with the SAM, and using the radar and cruise launcher, it can take out a missile reliably. However, the system breaks down when more than one missile is incoming in a short time frame. The radar launches another missile every 40 ticks by default it seems, so usually there will be 2-3 SAMs in the air, all targeting one missile. When one of the SAMs takes out said missile, the other 1-2 dash off to the side, presumably towards 0,0 instead of locking to the other incoming missiles in its range. Same issue also occurs if there are multiple SAM launchers involved; when the missile being targeted is destroyed, all other SAMs dash off, instead of taking out the other threats.

They only relock missiles within 30 meters to prevent from killing server performance. As some players like to fire 100s of these things when attacked.

https://github.com/BuiltBrokenModding/ICBM-Classic/wiki/missile-sam There is a config to change this range if desired.

There is also a plan to rework this system in later versions. As the current version is still mostly calclavia's old logic. With only recently getting an exact target feature via the radars. Along with a delay to help manage ammo.

I used configs to increase that range to 100 blocks, but it still seems to be incapable of relocking. In any case, cant wait for the reworked system

Quick edit; i simply increased the range to 300 blocks in configs and it works just fine now, sorry for bothering.

No worries, I'll still take a look as 100 should have gotten some results. If you do leave it at 300 I recommend also flipping on radar only mode. This way its not pinging every entity causing a degrade in server performance.