6 years old kid don't need to see what bullets do to flesh. Let's wait, at least, until they enter junior high school before that. The best way to avoid a gun accicent with a 6 years old kid is for the parents to have their gun(s) locked-up in a safe-box placed somewhere a kid can't reach
Although I agree to let kids be kids, I'm afraid that, a 6 years old kid bullied by three 10 years old kid, knowing this is a fight he can't win, that would he throw a punch it won't affect his bullies and they might kick his ass as punishment for trying to resist, if he can access dad's gun, might bring it just to scare them, thinking it's not loaded...
Firearms + kids is a recipe for disaster, end of story
No one made excuses for unsecured firearms. No one suggested showing a child violent crime photos. The Mythbusters simulated the effects of bullets on ballistics gelatin, and pig carcasses. I wouldn't suggest anyone, let alone a child to be subject to seeing violence towards another human without their, or their parents consent. You or I can go on youtube and see R.Bud Dwyer put a .357magnum in his mouth and blow his brains out on live TV, but I don't think it should be mandatory. As far as the 3 10 year olds, bullying one 6 year old, yeah, he'll take an ass whopping or 2, but at least he'll have some self respect, from standing up for him self, and if he has to, get 'em one at a time, or get a few friends, and make it 6 to 3 instead. There are all kinds of ways to handle the situation, but letting it continue, or running to a teacher WILL NOT fix a bully problem. Hell, if it were me, I would get my hands on a set of brass knuckles, and see how quick they bail after the first one goes out from one punch. Every friend I have, that hunts, has children, or had, in a house full of guns, and not one of them EVER had a kid that was obsessed with guns, and all of the ones that had sons, took them hunting from a young age, and all the kids went through the hunters safety courses and such, so you're mistaken, it's kids and ignorance that are a bad combination. Even though you should have enough common sense to lock up your guns if you have children in the house, you should never deny them information about them, and should educate them as soon as they are capable of understanding. You can't hide anything from kids these days. They get pregnant younger, commit crimes at a younger age, once they hit school, and start to talk to other kids, most of your influences are going to start getting questioned. You need to keep up on what they're up to, especially as the teen years come into play. The more you deny them, or dismiss them, the more they'll go elsewhere for the information. You can't teach them to be afraid of things like guns, or motorcycles, but they better damn well learn to respect them.