Having 2 teenage boys, and as past NRA instructor ..........

Might I suggest that a S&W or Ruger revolver with a swing out cylinder is easier to check to confirm an empty gun. I know, they should treat all guns as loaded....I'm just saying it's easier to check and confirm that a swing out cylinder is empty......

The Ruger single six is chambered for .22lr and .22mag;so it has a compromise barrel to handle both rounds....... so not the best for .22lr. accuracy.

Also if you are getting it as a gift....... he will have if for the next 60+ years........ I'd go for an older 17 or 18 or 6shot 617 4 or 6 inch