This already exists, in the Psionics Handbook. From the SRD:
Dislocator: The wielder of this weapon can attempt to dislocate a designated foe up to three times per day. On a successful hit, the foe must succeed at a Will save (DC 17) or be teleported 1-100 miles in a random direction. If the weapon misses, the use is wasted. Bows, crossbows, and slings bestow this power on their ammunition. Manifester Level: 12th; Prerequisites: Craft Psionic Arms and Armor, teleport; Market Price: +3 bonus.
Great Dislocator: The wielder of this weapon can attempt to dislocate a designated foe up to three times per day. On a successful hit, the foe must succeed at a Will save (DC 20) or be cast into a random alternate plane of existence (such as the Astral Plane, the Plane of Shadow, or even the Abyss). If the weapon misses, the use is wasted. Bows, crossbows, and slings bestow their effects upon their ammunition. Manifester Level: 18th; Prerequisites: Craft Psionic Arms and Armor, plane shift; Market Price: +4 bonus.
If you wanted to make versions with no save and/or a definite destination point, I'd be really careful since like has been pointed out, it can be insta-death depending on the circumstances. It's powerful enough as is. Hit a Fighter with a Dislocator arrow, and he probably is out of the fight for good. And, DC 17/20 Will saves aren't something to ignore.