Ancestral Weapon Mastery (Combat)Source Inner Sea Races pg. 201
You have mastered ancient techniques that increase the effectiveness of your race’s ancestral weapons.
Prerequisites: Base attack bonus +1, weapon familiarity racial trait.
Benefit: You’re proficient with all of your race’s racial weapons (the weapons mentioned in your race’s weapon familiarity racial trait). If you’re already proficient with any of those weapons, you instead gain Weapon Focus for one of those weapons as a bonus feat. Furthermore, if you gain Weapon Focus as a bonus feat with one of your racial weapons as a result of this feat, you can change which racial weapon your bonus Weapon Focus feat applies to by engaging in 10 minutes of practice with the new weapon. The benefits of this bonus Weapon Focus feat last until you choose to practice and apply it to a different racial weapon.