Ruger 10/22
Okay, I teethed on bolt action 22s, and they're great for training for accuracy and proper technique, safety, and all that.
I've trained dozens of new shooters on the Rugers, though, and there is nothing wrong with letting the old guy have a little fun. The way I look at
it is, yes, you do shoot more ammo becuase you CAN - but new shooters usually find that to be great fun. And this is for fun, right? I mean, you're not training anybody for a Palma match or to be a sniper.
An older gent is maybe a little less likely to get excited and do those things on the range that we find annoying like trying to see how fast a mag can be dumped while war fantasies play in his head.
And the Ruger is the most popular 22 ever built - millions made - sturdy, accurate enough, reliable... all that. Nothing wrong with the CZ, and that's a fine hunting rifle good enough for informal target shooting, but I'd let the guy
have some fun with the Ruger.
Good luck - it's great to share shooting with a new guy - even if he's not a kid.