Tumshie's Booming Bullet

You brandish the weapon used in the spell’s casting and make a ranged attack with it against one creature within the chosen weapons range. On a hit, the target suffers the weapon attack’s normal effects + 1d6+(Spellcasting modifier) and then becomes sheathed in booming energy until the start of your next turn. If the target willingly moves 5 feet or more before then, the target takes 1d8 thunder damage, and the spell ends.