Everyone's kids are different - when I was growing up, I had a regular arsenal of toy guns that looked real enough to give today's child safety "experts" a fit of apoplexy, but I never confused my toys with "real" guns . . . I got my first BB gun at age 4 (it was too big for me, I couldn't cock it myself, and had to tuck the buttstock under my armpit or I couldn't reach the trigger. I soon grew into it.) and my first .22 at age 7.I was not allowed any toy guns, or even water guns. Part of me thinks that availability of toy guns might allow kids to think a real one is a toy, without any real (eddie eagle type) of education.
Seventh grade brought me a Crosman 38C air pistol, age 13 and 8th grade graduation brought me a .22 Colt Diamondback, but I was years past my "toy gun" phase by then.
My folks did have a rule imposed when I was probably 9 or 10 that I disliked at the time, but looking back I found was very wise: When I was ALONE I could shoot and plink all I wanted, but if ANY other kid was with me, Dad had to supervise. They knew that the effective IQ of young boys is that of the smartest one divided by the number of boys present, and the likelihood of doing something stupid increases. (Fortunately, we frequently visited cousins in the boonies, so I had a chance to shoot outdoors . . . that and the range we'd built in the basement.)
Oh, one more thing . . . I grew up in Chicago, so keeping quiet about the number and type of guns in our household was taught early on.