Elemental Shot (5e Feat)
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Prerequisites: Proficiency in Firearms and at least one spell slot.
You gain the ability to change a bullet's damage type.
You can use your action to expend a spell slot to change the damage type of a number of bullets you are holding in your hand or loaded in a firearm you are wielding. The number of bullets that are affected is equal to the level of the spell slot you expend.
The damage type of the bullets changes to your choice of fire, acid, cold or lightning damage. The bullets revert to their normal damage type when you finish a long rest.