Arcane Railgun

The Iron beings to spin within your hands slowly gaining power. When the spell ends, either because your concentration is broken or because you decide to end it, the iron punches through the air with a crack with a low roar. Each creature within a 100-foot long and 5-foot wide line must make a Dexterity saving throw. A creature takes force damage equal to the total accumulated damage on a failed save, or half as much damage on a successful one. Objects and structures take double damage.

The spell's base damage is 12d8 with a range of 100ft. At the end of each of your turns and if you haven't released the spell yet, the damage increases by 1d8 and the range increases by 100ft to a maximum range of 1000ft.

Additionally, you are unable to willingly move while casting this spell. If you are moved while casting the concentration DC is doubled.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the base damage increases by 1d8 for each slot level above 7th.