Second most likely failure is not to remove the wrapping paper from the birds cavity. The inside of a turkey should be clean. No stuffing ect.
By the time the bird fully cooks it is dry like 4 glasses of water per serving dry.
Best way I have found deep fat fryer for 25 minutes.
However traditional oven method is 325 for 30min per pound a 10 pound bird needs to cook for 5 hours..... if you place the bird in the oven at 9 am it can be served by 2. Pm.