Need help with Arcane macro

Ok so I made a simple macro that is just to power down targets when you aren’t worried about mana, The problem is I use AHK and if I do it like:
/cast [nochanneling] Prismatic Barrier
/cast [nochanneling] Arcane Power
/cast [nochanneling] Arcane Missiles

It will just blast the hell out of the target and then wail on anything nearby. If I add in /cast [nochanneling][combat] Arcane Missiles, for some reason it ignores the [nochanneling] and just rapid fires missiles and drains my mana like crazy. It will fire midcast of the previous one. I tried putting in a space like [nochanneling] [combat] and no change.

I’m using it on a level 117 and pulling 7500 dps which is awesome! But I am trying to get it to work right and for some reason it isn’t. When it ignores the nochanneling I am hitting WAY higher DPS but burn through my mana in one target.

The full macro is below but I wanted to show the text of it so you all can see what I am talking about. I added in two more lines of Missiles and no matter what it just goes wild.

dCJ(baGEuv9suPERQyBqOMTuUju8lvQBlQStLAVKDJSFq(jQsddvXVPQbcLYqPidwvnCkWbrf6yICCujTqiTukQfJkYYLQhIkXtfwgu9CLmrrvtfutMcA6kUiuQEMOCDvPnIkQTIkyZqjTDiKpcL4RuO(mL6YsgjfYHbgnL8yQCsuvonkxtfDEi6UQW0ujVgcwjbRDsHjEng7MZZRXBTXfScyqROzPaplLszzkYxyf82gTtk447y57kWa6iT8VgYig2WsNXp)nKqFJyT2sryq54lV2igxbgGR75q1xmpTeS2jbRDsXTdSgO)d5DwaIQgJSpG(4zNxN8OnUIBhynq)hY7SaevngzFa9t48CHRDMIBhynq)hY7SaevngzFa9ptxzAFP42bwd0)H8olarvJr2hq)Z0vM2NkUDG1a9FiVZcqu1yK9b0)mDLPGl(CCcmcvHrfWqHQyxoeeQc0QncvHzgzNeQc4oJqOMKqva3zec1GlufCxinxTcSkbRrb3fst9ATeS2jf3dOBxtrvoKq)hYBb65o0OWmJSXfQct(1Gb46EbRrHPEHb46EbRrrmLbC(LCdZtkIIRVfnmqtJgfya0lOXhnvhrfnmpjunAKa
POWERDOWN

Talents are 2311133 and I’m running at 50ms

I have modified a lot of macros to customize them to my style but this is the only one I started from scratch so I may have missed something.

I don’t think it’s a problem with the macro function, but rather what you have in it!

Arcane missiles should only be used when clear casting procs (and it procs quite often)…it costs no mana when cast under clear casting, but costs 15,000 mana outside of that.

You would be better off using a mod key to fire arcane missiles, and replace those lines with arcane blast. Then have a different mod key to fire off an arcane barrage when you’re at 4 charges.