Lethal Operation Tips

Hello fellow miners, I have been trying all week to complete this week's Lethal Operation. I normally make it to wave 3 with a handful making it to wave 4.

My best builds so far have been a Driller full of corrosive or Heavy Gunner. Most of my gear is 65-72 mostly focusing on adding HP, armour and damage.

Any tips are greatly appreciated. Rock n Stone