Yes, Sam's pretty, pretty princesshood is indicated by his choice of firearm even more strongly than by his toothbrush color. *nod*

Although, I'm reasonably sure that it was originally Dean's gun (he uses it a few times in S1 before it becomes the one that Sam uses all the time) which leads me to believe that Dean just has a thing for trolling pawn shops for the pimpest weapons he can lay hands on. Possibly while running errands to find Sam a new pink/purple toothbrush.