When our oldest boys were young, we never let them have toy guns. It was a toy that we never wanted them to have. Why would we want them to go around pretending to shoot each other?
Well...I think there is something built into boys that they simply MUST have a gun of some kind. I figured this out when our oldest discovered his finger gun! We're thinking..."where did he get this idea from?" Later he found other "guns" to use, even building them from Legos. We soon gave up on that idea and decided to teach them gun safety and self-control...you know, the kind that keeps you from shooting your brother "because he's driving me nuts" kind of self-control. So, now several years later they all have the traditional BB gun and they're learning to target shoot in the back yard, always being careful of what's behind the target as well as where all the other people and animals are playing. It's working well for our family and it might for yours too. Of course, the younger boys don't have BB guns but they do enjoy their "pop" guns and rubber band guns. :)
I wonder if their need for a gun could have been the result of the many John Wayne movies, they've seen...I'm a bit addicted to them.