I wish my son could have started that soon. He wasn't even supposed to be in the woods with me til age 11 during deer season. He was but it was a big fine if he was caught. When he got his 1st deer it was a nice 22" heavy racked 9 point and he literally had to sit on my lap to take his shot.
My dad started teaching us gun safety at 4. We were shooting 22's at 5. We shot only under supervision til we were 10 then we could hunt rabbit and squirrels by ourselves but only on grandpa's and one of his neighbors farms. I raised my son the same way.
Or the one that got away? Bought my son a Remington 7600 in 260 Rem. Extremely accurate for a pump rifle. I had the chance for a 2nd one, consecutive serial # and didn't. Kicking myself to this day.