You will have a great rifle. Make sure he gets one with the BOSS. Non BOSS Brownings generally will shoot around 1/2 MOA. BOSS guns can shoot under .3 MOA.
This assumes precision rifle loading techniques.
He may have better luck with the 300 Win Mag. Less recoil, a lot less powder and better component choices. Nearly the same trajectory within normal game ranges.
The 300 Win Mag has been a winner for many years. He can even get a heavy barrel rifle that will give stunning accuracy and 243 recoil. It can push a 190 gr Match or hunting bullet at or near 3200 fps.
If one needs more power than this, he is likely going to Africa or Mars.