Alternatively, you could just measure the distance between the weapon and target, round up to the nearest 10' and do it as falling damage
I was thinking about that... small problem with that was.. scene damage. Can a wall actually take fall damage? I'm going to tweak it to 6d6 Sonic. Closest thing I could find that matches what I'm aiming for.
Koala's Super Secret Ultra Classified DM Cannon-o-DOooooooOoom!1!!
6d6 Sonic* | 1-7 / 19-20 | 1M2 | 24 | 250 ft | S / 2h | MAS / QKY / SLA | 41.2 lbs
* +10 vs. Scenery