SRD:Psychokinetic Burst

Psychokinetic Burst: This weapon functions as a psychokinetic weapon that also releases a blast of destructive psionic energy upon scoring a successful critical hit. In addition to the extra damage of the psychokinetic ability (see above), a psychokinetic burst weapon deals an extra 1d6 points of damage on a successful critical hit. If the weapon’s critical multiplier is x3, add 2d6 points of extra damage instead, and if the multiplier is x4, add 3d6 points of extra damage. This extra damage is ectoplasmic in nature and is not affected by damage reduction. Bows, crossbows, and slings bestow this ability upon their ammunition.

Strong psychokinesis; ML 12th; Craft Psionic Arms and Armor, concussion blast; Price +2 bonus.