Brenatto's Voltaic Bolt

The next time you make a ranged weapon attack, the weapon’s ammunition becomes charged with electrical energy. Make the attack roll as normal. The target takes 3d6 lightning damage on a hit in addition to the weapon’s normal damage.

The piece of ammunition then returns to its normal form after the attack whether it hits or misses. 

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage for both effects of the spell increases by 1d6 for each slot level above 2nd.