There is no best ammo for Canada geese for any one gun, you need to try several brands and shot sizes and see which one patterns best.
Pappy's right (John S). Remember to try different choke tubes as well.
I shoot a Browning Silver Autoloader with a factory Mod choke tube along with 3" Hevi Metal #2's. Patterns like all get out. But, I've tried Kent 3" #2's and it doesn't do any good out of that gun. Your gun on the other hand may actually shoot/pattern Kent's real well.