I don't have a clue what could be wrong with your gun all of a sudden after all these years, have you tried another choke? might be something with it. If you don't find what is wrong with it soon there is still time to put a scope or red dot on it and get it patterned before turkey season starts, if that is your sons only gun. From what I have seen and heard that Winchester 3" #5 should give you a good pattern. Wish I could be of some help, Good Luck