How much can a sniper rotodrone aim, anyways? Treat pilot rating as willpower?
Unfortunately, a drone on its own isn't getting above a base dice pool of 14. That's pilot 6, autosoft 6, smartsoft. That's not terribly accurate.
Thus, if you really want to kill things, defense penalties are your friend. Einfield AS-7? Burst fire, wide choke. -10 dice to defense. And against multiple targets. Go out towards the edge of your firing range (probably long; extreme is a huge penalty) and you're taking damage penalties, sure, but you're hitting more people at once, all of them losing dice for defense against later, stronger shots. And, mooks in numbers are liable to care about the damage.