In one example... changing from Kidds Overloader to OS6, the max range of your weapon red line on the radar should increase due to the +range from OS6, however it decreases instead.

Range still seems to work it's just the red circle should be larger.

i hade similar problems, iirc re equipting a item on your ship helps o.o

This is probably because swapping overloader isn't enough to cause a full hardware recalculation (and thus range calculations for your radar).

Try fiddling with your shield/equipped weapons when you swap and see if it updates. XD

or update the radar ya know.

or fix the game

Yep. the red circle of your range has no bearing whatsoever on the actual range you may or may not be able to hit a target at. It does change when you change weapons, but I think it only reflect the range of the weapon, not the actual range with tweaks, augs, bonuses and the like.