The magic crafting, mountain cracking Wizard just spent years beating how to cast Read Magic into your PC's head. Then he turns you loose with the ability to memorize one spell a day just so the Party you hang out with between feeding the wizard's pet Xorn and scrubbing glass vials in the laboratory clean can use you as a meat shield fifty feet into the dungeon. No. If you are going into that dungeon it will be because the Wizard wants you to go fetch something important like a giant spider eyeball, the whereabouts of his previous apprentice, the heart of nekron, or stomp the competition. He is going to hand you a Scroll of Dimension Door so you can bail on the party if it looks bad.
So why wouldnt your teacher, master, mentor, and Patron arm you with more than how to read a scroll you need to tear from the cold dead hands of the other guy's apprentice from the get-go? The ring/wand of spell storing seems like the sort of thing a Wizard would hand an apprentice so they can fill it full of magic Missile spells and take out a dragon.
Gunblade of Grindal
A Magic firearm/dagger which can store up to six spell levels: six magic Missile spells or two lightning bolt spells. The weapon can be used as a dagger (1d4).