I had a formidable "arsenal" as a child & as an Army Cadet was using genuine lethal weaponry (under close Military supervision) by the age of 13.
By the age of 19 I was active in the peace movement.
It seems to me that by banning toy guns you instill them with "the lure of the forbidden" in children's eyes.
This is likely to be counterproductive.
That having been said I DO very much approve of the American habit of only manufacturing toy guns in completely unrealistic colours.
Most years We holiday in Continental Europe.
Toy guns are ubiquitous in shops there & tend to be extremely authentic loooking.