Take a look at the Savage 220’s if you dont do the Browning BPS. It can shoot very accurately out to 150 yards with the Remington Accutip Slugs. The slugs have been hard to find but the Remington Factory is producing them, just expect to pay $20 a box right now. The shotgun is a bolt action, so it has a bit more kick then a semi auto, but it could be a reliable shotgun for years for him and they make left handed versions.
I have mine paired with a Vortex Diamondback 3x9x40 scope.