What about a psion with schism, Dorje Mastery, Dual Dorje Wielder (from CPsi), a psicrystal, and ranks in UPD? You get to fire off two dorjes at a time, your psicrystal gets its own dorje to use, and so does your schism (and if your psicrystal has been altered via metamorphosis and you share schism with it, it can use an additional one, too).
That's up to 5 shots per round. And note that, unlike wands, you can get dorjes of 5th level and above.
Get Quickdraw and eternal dorjes (ie, eternal wands, but with psionic powers stored in them) to keep this from being ridiculously expensive.
Added in with a swift-action power, Linked Power, and one other power, and you can fire off a total of 6 this round, and up to 7 next round.