From D&D Wiki
The AM00-Buster may be something for humans to laugh at, but when they find that it can fire spells...well they'll be running alot more fast then normal. Augmented Mega 00-Buster allows warriors or spell caster to store spells and call upon them later. It's mainly used as an offensive weapon but can also be used for support or defenseive purpose.
Prerequisite: Ability score 13 Intelligence or Charisma with atleast 2 Ranks in Concentraction and the BM1-Buster.
Benifit: You can store up to 3rd level spells into your buster, none of which maybe higher then a 5th level caster. You can store a number of spells equal to 1/4 your level + Intelligence modifier (Minium of 1 + mod). Target spells work normaly and some area spells may be modified. Like Burning hands and Color Spray may be fired as a line affect up 60 ft, these are the only two affected so far.
Special: If you are required to make a touch attack or an attack roll against an enemy, your over heat property applies as if you had an IM1-Buster, but the save is the spell DC instead, because you are not firing a charged attack. You can store scrolls or have spells casted on it to be stored equal only to a number of days equal to your Intelligence modifier, after which you must make a save or the weapon discharges it. Stroing scrolls in it takes 1/2 an hour for each level before they can be fired. You do not suffer from spell failure when firing a spell, but follow the spell guide lines as if you were the caster. If yourself cast a spell then it dose apply.
Normal: You can't use spells in your buster in this way unless you have this feat. Also Spell storing will not affect Burning hands and Color Spray as mention above or add to the limit.
Role Playing: As mention above the feat only affects two spells. As for target spells the describition may vary form player to player. Example: The Warforged Hotmetal is launching a magic missile attack from his AM00-Buster "His arm cannon glows a violet blue as the interior barrels started to spin, a sudden burst of three magical bullets shot forth and locked on to its target. They weaved between friend and foe before finally exploding up their target."
Flavor Text: "*Yawn..blink, blink* Darn-it, ok who here painted my buster like a cow again!!?? *Charging sound: Peeeww*"