Going to have to experiment a bit with the ammo vs heatsinks, but this will most likely be my Rancor build.
Oh, never quite got back around to it, finished the BAS challenges and got burned out running assaults in QP
Definitely think it needs less ammo and more heatsinks now, really not a fan of how this build plays though, don't really have the speed to control my engagement range or the hardpoints to bring any meaningful backup but I can't think of anything else to do with a Rancor.
My version. What to do with a rancor: Treat it like a MAD-IIC-B. Two ATMs are plenty, then add a bunch of supporting lasers