Crossbow Sniper

 
Prerequisite(s): BAB 1+, proficiency with Hand, Heavy or Light crossbow, Weapon Focus with Hand, Heavy or Light crossbow
 
Benefit: When using a crossbow for which you have the weapon focus feat, you gain a bonus on damageequal to 1/2 your Dexterity bonus. If you have the Skirmish or Sneak Attack class ability, the maximum range at which you can make such attacks increases to 60'.
 
Source: Players Handbook II