First of all, my opinion on this level: This is what I consider to be the second-hardest level in the entire Descent Series, which is why I am giving it special attention...
If you shoot the BS at the forcefield at the end for those two tail bots, they take super heavy damage and die.
The trick is to fire a slow-moving projectile (preferably a flare) at it, then move out of sight before it hits, to it zaps itself instead of you.