I've always been really adamant about staying clear of allowing my children to purchase or make or pretend something is a gun for very obvious reasons. I've instilled this in all of my children since they were really young.
DS who is 4 made a gun out of Lego the other day and I discouraged it and started making other things out of the Lego and he followed (cars, houses etc).
I don't know if they discourage this at DS's kinder, but is it my place to say anything to them? I am really not happy with him having anything to do with guns.