I'd get him the Ruger American in 6.5 Creedmoor. Even though it's a compact, it's probably going to be a bit too long for him. Get a long eye relief scope so he can still get a full sight picture even though his head will be further back. This is the one I bought for my son: https://www.midwayusa.com/product/1009529795

After the rifle was set up, I'd have him practice with nothing but a 22 or similar so he gets comfortable shooting. Make it fun for him, have him shoot balloons, eggs, something other than paper all the time. Before hunting season, I'd get some low recoil ammo. Have him wear good muffs and plenty of clothes to help with the recoil. Let him shoot some water bottles or such so he's comfortable and confident with it. Don't want him afraid of it.

This is very similar to what I did with my son when he was 6. I bought him a Savage youth 7mm08 and down loaded a 120gr BT using H4895 pushing about 2400fps. To me, felt recoil was less than a 243. As he got older, I added powder and put on a regular scope. He killed more than 20 animals with that setup before I sold it to a buddy for his son. His 7 year old son killed his 1st deer yesterday using that rifle.

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