There's a lot that can be said for a plain old 700 heavy barrel 243 with it's 9-1/4" twist. Launching 105's and 107's at 3000ish work well with little recoil. There are some VLS models out there with some recoil mitigating weight to them that would be good for a youngster.

"after the bullet leaves the barrel it doesn't care what headstamp was on the case"
"The 221 Fireball is what the Hornet could have been had it stayed in school"