In all your travels through the U.S. , have you ever seen any 300 t0 500 pounders ?
The guys that I know that go regularly to the U.S. to hunt them have never seen them that big, my wife's nephew a taxidermist being one of them , goes with two others and they bow hunt them.
Their largest was a 250 lb. boar in seven years hunting in different states.
It is possible that they could grow that large under the right conditions, but there would be very few of them because if there were many , we would be hearing about them often, which we do not.