I don't think Returning can be put on a bow:
CRB wrote:
Returning: This special ability can only be placed on a weapon that can be thrown. A returning weapon flies through the air back to the creature that threw it. It returns to the thrower just before the creature’s next turn (and is therefore ready to use again in that turn). Catching a returning weapon when it comes back is a free action. If the character can’t catch it, or if the character has moved since throwing it, the weapon drops to the ground in the square from which it was thrown. Moderate transmutation; CL 7th; Craft Magic Arms and Armor, telekinesis; Price +1 bonus.
Bows aren't thrown weapons. Neither are arrows.
Unless you mean a different enchantment?
Arrows also don't count as thrown weapons. They count as ammunition (which has its own special rules) and can also be used a light improvised melee weapon.
There is a spell called Abundant Ammunition which is cast on a quiver or pouch that contains nonmagical ammunition that basically allows you to not lose ammunition for the duration of the spell. I don't think there is an enchantment currently that matches this spell.
If this is a homebrew game, you could talk to your GM about being able to craft a quiver of Abundant Ammunition by getting a spell caster that can cast Permanency and Abundant Ammunition. In PFS you can't do this.
Note again, Abundant Ammunition only works on non-magical ammo.
Another alternative is Durable Arrows (available in Alchemy Manual and Elves of Golarion): http://www.archivesofnethys.com/EquipmentMiscDisplay.aspx?ItemName=Arrow%20 (durable)
These arrows cost an extra 1 gold apiece. In PFS, you have to buy 50 custom arrows at once, but you could buy 50 Addy Arrows for 3,000 gold, or 50 Durable Addy Arrows for 3,050 gold, and be able to retrieve your arrows after use (and you manage to slay whatever monster).
