Ahh, trig time!
Darn it... 6am... Don't feel like trig!
Here's a simple solution.
Every tick:
Target: set position to turret.x,turret.y
Target: move at angle angle(turret.x,turret.y,mouse.x,mouse.y), distance distance(turret.x,turret.y,mouse.x,mouse.y).
This should do what you want.