I got my first real gun somewhere around 6th/7th grade. I still remember I was in the cub scouts and the local cub scout/boy scout group brought in soemoen do teach a hunters safety class and I passed it easily because my father had taught me a lot of safety with my little bb gun I had before that.
I think thats why out in the country you have so much less children shooting other childen. We grow up around guns so we don't try to sneak and play with them when parents are not home because were already familair with them.