One single character can't activate a Wand of Magic Missiles fifty times in one round.
It would take fifty characters, all standing in formation, each delaying his action. Each one uses the wand (standard action) then passes it to the next character (move action) then drops prone (free action) to avoid obstructing line-of-sight for the next rank in the formation.
Fifty 1st level wizards passing around a Wand of Magic Missiles can put a big hurting on almost any character, around 175 HP on average.
Alternately, instead of activate wand/pass/drop, they could grab the wand (move action), activate it (standard action), drop prone (free action).
Dropping prone isn't strictly necessary since intervening creatures don't block line of sight, but it's just plain more fun to imagine the domino effect.
Remember, sorceror is the favored class of kobolds.