With all the other things grabbing for our kids' attention these days we have to get them started earlier. Minnesota has the apprentice hunter program, which means your child doesn't need a firearms safety certificate as long as you are with them. I was shooting guns at the age of 8, my daughter got her first .22 at 6, is now 9 and has shot a .22, muzzleloader and .17 hmr and knows barrel and trigger control better than most adults. Gun safety starts in the home with repetition, taking a class is no replacement. I'm taking my daughter out turkey and deer hunting this year with a crossbow and we're both SUPER excited! My kids are excited to see me come home with a deer and keep asking when they can go too. If I have to wait 3 years I know something else will grab their attention before the woods does.
But it all depends on the maturity of the kid, which the parent should be able to gauge.