The A300 is a good gun, made in USA. Cosmetically very plain, they work well for hunting purposes and are good value for this purpose. The A400 is Beretta's flagship auto shotgun, great design, well made, beautifully finished, they are one of the world's finest autoloaders and will last indefinitely, even in competition where they are heavily favoured. You pays your dime and makes your choice. The A300 is built to be a good reliable hunting gun at a competitive price and benefits from the Beretta name and reputation. The A400 is simply built to be the best by one of the oldest and most trusted manufacturers in the world.