For deflection shots, you need to be in close. Like, really close. If you're on someone's 6 matching their turns and want to shoot, you're best off using MG's until they start to fill your windshield. When you're attacking someone and expect them to break (as in they've seen you), you want to guess which way they're going to turn (usually pretty easy), and point your nose in that direction a little bit. Not a whole lot.. you still want to close on them, and don't want your lead to be completely obvious. When they start to break hard, that's where you maneuver in such a way that they'll be crossing in front of your nose at high deflection (90 degrees, or thereabouts is the sweetspot for taters) at d150 or less.
Once you learn how to get people to cross your nose up close at high angles, it's just a matter of getting your trigger timing down so as to minimize the amount of ammo you use. And one other thing... I find it MUCH easier to connect with taters unzoomed.
P.S.
38's/110's/mossies should be your first choice in targets, if you have the luxury to choose. Especially 38's... so easy to hit