Having owned or meddled with most of the rifles listed.. I would choose a Tikka T3x Lite Stainless. NO question asked.
Howa/Weatherby next two options... way down on the list...
308Win
Stainless
Tikka T3x
Leupold 2.5x20
Sportsmatch rings
2 spare magazines
150-165 grain bullets
Rifle and optic for a lifetime..
Can buy pretty rifles later, if it turns out he loves hunting.
The 308 can easily be chopped to 16" and fitted with a silencer when he is older, and still make quite easy 300 yard shots.
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