Alright. So that helped. I now got the distance variable working so it reacts and accelerates when the Chaser gets close.
System 0<distance(Chaser.X, Chaser.Y, Chased.X, Chased.Y)<500 Set bullet Acceleration to 500
How would I make it choose a direction. My current action is
Set Bullet angle of motion to random(random(Sprite.8Direction.MovingAngle+random(180))
But all it does is cause the Chased to spiral around and freak out... which of course means it's not getting very far.
I'll add more to slow it down when the distance widens. I imagine adding a path finding behavior will allow it to move around obstacles.