Bring Out the Big Guns is challenge within Eridium Blight to destroy five Hyperion turrets. It is worth 1 Badass rank.
Turret 1: On the road from the Fast Travel east. The turret is at the first door on the right
Turret 2: Beyond the door by the first turret, and on the road under the pipeline, the tower with the turret is visible to the right.
Turret 3: On the gate by the entrance to Arid Nexus - Boneyard
Turret 4: North from the entrance to Arid Nexus - Boneyard, the turret is on the tower behind where the Hyperion soldier spawns.
Turret 5: On the tower on the south side of Blake Bridge.