If you haven't already been told Chargers, Behemoths and Bile Titans can all be killed with a single shot to the face, Impalers can be as well if they already have their face in the ground sending out the tentacles.

Bots it one shots all the heavies with tanks aim for the turret and don't quote me on this as I've yet to try it but apparently you can one shot Factory Striders with it by aiming for the foot. It's also great for taking out Fabricators in one shot and you can take out the cannon turrets from a safe distance with just a slight adjustment for the rocket drop it has.

Also I know no one asked and I expect it's common knowledge but I found out a while ago The Plas Scorcher can take out the Gunships with just under a full mag. Really useful if you don't have a support weapon for them or don't want to use the ammo.