Persistent Melf's Acid Arrow?

[SangoProduction]

http://www.d20srd.org/srd/spells/acidArrow.htm

OK. Is there a way to make it so acid arrow has a fixed range? Does "Touch" or "Line of Sight" work for that? I think there's metamagic to change the range to those.

(And yes, I know there are much better things to do with a 8th or even 5th level spell slot, but 24 hours of burning sounds kinda hillarious. Also, we need to eat through a city's walls for the army. Sounds like this would work well....AGAIN! I know I could probably do it easier with some other spell, but still!)

EDIT: Oh, melf's acid arrow is a second level spell....and Persist is +6. for some reason read +5. Changed. OK. So it's going to require 8th level spell slot by default. OK that...yeah. Messing up by 2 whole spell levels is massive. Nevermind.

Is there a better spell that I can do this idea with?

[MaxiDuRaritry]

Ocular Spell changes the range to a flat 60 feet.

A psion could use a sonic energy wall. It'd even ignore the wall's hardness.

You could also just hire an initiator with mountain hammer or something.

Or summon a creature that can burrow into stone, like an earth elemental or a thoqqua.

[DarkSoul]

Persistent Spell is +6 spell levels, so you're starting at level 8.

Disintegrate will likely be a better use of spell slots. The wording of the spell says it only affects one target per casting, which opens up the argument for applying Chain Spell to it. A 10' cube of stone plus at least 17 5' x 10' slabs simply disappearing would provide a 20' square opening 20' deep in 6 seconds, if it doesn't collapse the wall completely. Even if you can't chain disintegrate, single castings are still going to be more effective than persistent acid arrow.

That's the route I'd go, because Chain Disintegrate would be pretty impressive if you can get it approved.