The character transmutes up to three pebbles, which can be no
larger than sling bullets, so that they strike with great force
when thrown or slung. If hurled, they have a range increment of
20 feet. If slung, treat them as sling bullets (range increment
50 feet). The spell gives them a +1 enhancement bonus to attack
and damage rolls. The creature using the stones makes a normal
ranged attack to use a magic stone. Each magic stone that hits
deals 1d6+1 points of damage (including the enhancement bonus).
Against undead creatures, this damage is doubled (2d6+2 points).