Artificer bonus feats

Artificers can select bonus feats at levels 4, 8, 12, 16, and 20 from the following list:
 * Augment Summoning
 * Construct Essence
 * Adamantine Body
 * Improved Fortification
 * Mithral Body
 * Mithral Fluidity
 * Improved Critical: Ranged
 * Power Critical: Ranged
 * Weapon Focus: Ranged
 * Point Blank Shot
 * Rapid Shot
 * Improved Precise Shot
 * Precise Shot
 * Shot on the Run
 * Any Dragonmark of Making
 * Any Skill Focus
 * Any Metamagic Feat