Lol 3 seconds in the cross hair, that means your a dead man for having a little red dot on your head for so long :P
Contest sounds great. Maybe to make it special/different might be to have the theme of having them create a character in the comic with some background, have the winner's dude added in as a side character or even a guest appearance on the news show.
On average, a pilot can keep his target centered in his crosshairs for 3 seconds. Aircraft guns are sometimes rated in "3-second weight of fire," describing how much mass they can deliver in 3 seconds.