Imbued Spell (3.5e Equipment)
From D&D Wiki
Imbued Spell: This enhancement functions similar to spell storing with the following changes. Instead of preparing the spell and placing it into the weapon, the weapon becomes imbued with the spell. A single spell per imbued spell enhancement is permanently a part of the weapon.
Ranged weapons imbue the spell onto the ammunition upon loading, but lose the ability if weapon is unloaded by any means other than firing. Once the ammunition has been fired, and the spell used, the projectile becomes normal again (a miss still uses the spell).
This ability functions 3/day.