This is not how forums work. You ask about two different cartridges and then the replies should throw both of those out the window and tell you to get something else.................. Ill go with the .375 H&H. Will do anything he wants, wherever he wants and relatively mild recoil. ;)

Do you reload? Will It be a life time gun that might some day be a long range shooter also? If he is experienced at shooting or even moderate padi-wan go with a heavy barrel and great glass and he will be set for a long time. I own both rifle calibers and love them. 270 and 308 will both reach out a long way. My 270 happens to be me 200 and under range and slim barrel Remington. My 308 is a 26" bull barrel long range shooter and fun gun.

7-08 is right between both and offers more versatility in bullet grain sizes.

Well hell, how bout 338 lapua?
Question was 270 or 308. Not 7-08. And if not reloading it is not as versatile as ammo is harder to find.

My "go-to" deer rifle is a 270W. I had the same decision some time ago that you do now. I bought him a 20" carry-around all-weather 308. Latter when he could afford his own rifles, he bought a nice wood stocked 270W. Now, He hunts with both depending on his hunt conditions.

Both. Discussion over.

Get him a 270. You can share ammo and he has shot a 270. If he ever starts reloading when he grows up he will give you some ammo for being a good dad.

Give the boy a copy of "The Hunting Rifle" by O'Connor. After he has read that he will know what he wants.

My first CF rifle was an old Remington ADL in 270. Killed an absolute mountain of game with that gun. Later carried a 788 in 308 (and still do). Kinda partial to a Montana in 308 these days when the going will be steep and long.

No wrong answers here.

I agree with the majority and say the .270. I've owned and hunted with both and my experiences make my confidence level higher with the .270.