Accelobolt

You touch a small object, causing it to begin spinning rapidly in place. As a bonus action you can release the object, causing it to rapidly accelerates towards a target of your choice within range. the target makes a Dexterity saving throw to deflect or resist some of the impact, taking 1d10 bludgeoning damage for every 10ft of distance between either the target & the caster or the target & the maximum range of the spell, whichever is greater (see table below), and half damage on a fail. You may choose to increase the casting time to 10 minutes, increasing the spell's range by 20ft for every minute you spend casting the spell.

10ft: 1d10        60ft: 4d10
20ft: 2d10        70ft: 3d10
30ft: 3d10        80ft: 2d10
40ft: 4d10        90ft: 1d10
50ft: 5d10    

This spell can target creatures through 6ft of wood, 3ft of stone, or 6in of metal unaffected. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the range of this spell increases by 20ft per spell level above 3rd.