Good question..
There were a large number of Springfield 03's made and not all were created equal. If you can get the serial number of the rifle, and what arsenal it was fabricated in, you can determine whether it is one of the stronger actions. P.O.Ackley, in one of his books, identifies which are good and those that are not so good. I don't remember what the serial number range and what arsenal made the best ones. Maybe someone will come along and provide that info. But, it's good that you are asking as the 300 Win is a bit more powerful than the 30-06.
Don
P.S. Edit: If the action is drilled and tapped for a scope, and the bolt is lowered for scope clearance, and a new safety added, the rifle might be worth buying just for the action at that price.