DS picked this up from other children - we don't play with guns. Then DH started to play 18 rated shooting games when DS was playing in the same room, so I can't really just blame other children any more. DS and I discussed that guns can hurt people and hurting people isn't a kind thing to do. So after a little while, he realised I stopped playing if he started using something as a gun, we talked about that I don't like being hurt, he has stopped. With me, at any rate.

I have no problem with toy swords or toy guns. Just so long as they are used responsibly and not to hurt others. Just to playfight with agreed rules of conduct.