Brenatto's Voltaic Bolt

The next time you make a ranged weapon attack during the spell’s duration, the weapon’s ammunition, or the weapon itself if it’s a thrown weapon, crackles 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 or half of the lightning damage as much damage on a miss.

The piece of ammunition or weapon then returns to its normal form. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage for both effects of the spell increases by 1d6 for each slot level above 2nd.