I would probably prefer 8's to 9's in a 28-gauge, but they will be fine. The 1-oz. 28-gauge load that the previous poster mentioned should smoke targets, I've used that load with 6's to kill a lot of pheasants and chukars, they are impressive!
The only downside to 28's are the cost of the shells, but if you shop around- you can find them reasonably enough. I think the 28 is my favorite shotgun to shoot! Good luck to the young fella with his!
