Thanks for the comments guys!

My kids live here on our little 40 acres, with thousands of open acres around us. My 4yr old boy and his 6yr old sister often accompany me on walks and rides, with their rifles in hand. The 6yr old girl -- she was making hits at 200+ yards with her .22lr rifle at 4-1/2yrs of age!

They'll definitely be running central fire rifles by age 10.
We'll see if the boy gets his .375 double rifle wish, but by his age I was earning money independently so I won't be surprised.

Cheers
Tinker