From Compendium of Worldly Lore
Needs review
Source: Player's Handbook II
Description: You send a powerful shot cleaving through your enemies.
Prerequisites: Point Blank Shot, STR 15, Base Attack Bonus +10
When you make a ranged attack with a projectile weapon (such as a bow, crossbow, or sling), you can instead choose to unleash a single, mighty attack that blasts through multiple opponents. This attack requires a standard action, and your shot takes the form of a 60-foot line. Make a separate attack roll against each creature in the line. If struck, creatures along this line take damage from your shot, though any extra damage (such as from a sneak attack or a flaming weapon) is applied only against the first creature struck.
Special
A fighter can select Penetrating Shot as one of his fighter bonus feats.