Despite what others may say, just go for radiation on the shildeg. You can mod for corrosive AND radiation, so you can kill bombards a lot easier. you also get a second elemental for [Condition Overload], so you kill heavy gunners faster as well. [Weeping Wounds] for status, so you can use your elementals for extra damage. Replace DC with [Molten Impact] or [Healing Return] if you're using Naramon.