Effects Table for Rune Bullets

In an effort to spice up what occurs when a Gun Mage makes an attack with a rune bullet, I've devised this table. It represents the nature of what a Gun Mage is, a spellcaster who is chaotic and unpredictable, channeling her magic innately into rounds, uncertain of the results.

Whenever the Gun Mage makes an attack with a rune bullet that contains a spell of her highest known spell level, she must roll on the table below. For example, a level two Gun Mage's highest spell level known are level one spells. So, whenever she fires a spell level one rune bullet, she would roll on the Effects Table.



Effects:
Juiced Round: Rune bullets are finicky, and a Juiced Round results when something has gone wrong during production. Either too much powder or too much magic has been put into the bullet, and the result is unpredictable.
-Backfire: The spell goes off prematurely the instant the shot is fired, exploding through the hammer into the face of the shooter. Roll for saves as appropriate to the spell being cast, as if the Gun Mage who forged the round had cast the spell.
-Powder: The bullet has a few pellets to many of gunpowder, but still fires successfully. If the attack hits, the damage deals double base damage (not the additional force damage from a spell) as the bullet impacts harder.
-Potency: The spell that was entwined with the round has some how been granted further potential, the resulting spell damage from a successful attack is doubled (3d6+3 becomes 6d6+6, etc).
Internal Explosion: The powder mixture for the round was far from correct, and the bullet explodes before the spell has a chance to go off. Deal normal weapon damage (excluding the force damage from a rune bullet) to the weapon itself, as fire and steel scar the inside of the barrel.
Spell Fizzles: For whatever reason, the spell fails to go off when the bullet is fired. Ignore the bonus force damage for a rune bullet and any subsequent spell effects from the attack.
Normal Firing: The bullet, force damage, and spell function correctly and nothing extraordinary occurs. Every cantrip rune bullet functions this way.
Alternative Spell: The attack goes off without a hitch, except for the fact that the spell inscribed into the rune bullet was the wrong one. Roll randomly for a new spell of the same level off of the Gun Mage's spell. If the same spell is rolled, roll again.
Additional Spell: The fates have blessed this round with exponentially more potency than the caster intended. When making the attack, roll randomly for an additional spell (as for the alternative spell effect) and add the effects as if the two spells were being cast simultaneously. Having the same spell twice is permitted.