toy guns

So this weekend my younger brothers can upstairs to my house to show my boyfriend their new BB guns that my dad bought them.  There were two things that I disliked about this situation. One that it really annoys me that my dad buys my ten year old brother guns, and not even those little BB guns, there like the huge automatic.. blah blah blah.. I don't even remember the name of them I just saw that they were guns, big and didn't really care for them. The second thing that I disliked about this situation is that my daughter asked for one.
 At this point I didn't want to seem like I'm such a mean mom that doesn't let her daughter play with a "boy toy", because to me guns are more of a boy toy then a girl toy and I usually encourage my daughter to play with boy toys. Anyways I didn't want to seem like that to my daughter or have her question why I let her play with other boy toys and not this one, but this is a time, as mother, where I thought "where do i draw the line of what "boy toys" she could not play with."  As a mother I love that my daughter  isn't to girly or a complete tomboy, she has a good balance, not that I would really mind if she was either or , but I see myself in her, this was the way I was. So of course she asked for one and I said no, she got upset and of course her dad found a smaller one to give her. So all the boys and Juliza went outside and shot at some paper target that they has also bought.  I love that my daughter likes to interact with boys and that her and her dad and young uncles were able to bond, but I just don't like the whole gun idea. I also understand that its good to have children interact with different gendered toys, As Isabelle D. Cherney explained, play assessment shows that this qualitative research helps increase a more complex interaction and that its important because it opens up more possibilities of complex interaction and cognitive development and that is all great and all but I still don't feel comfortable with my daughter using this specific toy because of the fact that it is a DANGEROUS toy that she can become hurt from. As a typical boy toy exciting and dangerous, it might cause my daughter happiness, but if she would have gotten hurt, I don't know if I'd be upset and say "I told you so" to her and her dad or be upset with my self for not completely stopping her from playing with the gun.. I guess I was torn between her acceptance with her dad and uncles,who usually never want her to participate because shes is a girl, and with the idea of her happiness and her safety..