Needs review
Source: Player's Handbook II

Description: When your target is busy dealing with an ally's melee attack, you strike.

Prerequisites: Base Attack Bonus +4, Point Blank Shot, Precise Shot, Skirmish or Sneak Attack

By firing just as your ally connects with a blow, you take advantage of the distraction to strike the same enemy when his guard is ruined. If you ready a ranged attack to occur when an ally strikes a particular target, and your ally succeeds, that target loses his Dexterity bonus to AC against your attack.

Special

A fighter can select Deadeye Shot as one of his fighter bonus feats.