Improved Called Shot

You are skilled at landing blows right where you want to. 
Prerequisites: Int 13, Combat Expertise 
Benefit: You receive a +2 bonus on attack rolls when making a called shot. When taking a full-round or standard action that gives you multiple attacks, you can replace a single attack with a called shot. You no longer need to make a concentration check when attempting a called shot. The penalty for attacking targets who moved more than 5ft in their last round is reduced by one, becoming -2. You may still only attempt one called shot per round. 
Normal: A called shot is a standard action so it can not part of a full-attack and a concentration check has to be made to attempt a called shot unless you have the Weapon Focus feat.