I did my first turkey on my Akorn this year and I used a Turkey Canon for the cook. I did a 13lb bird and it was done in only 90 minutes, pulled at 165° in the breast and 185° in the thigh. Best turkey I have ever eaten.
That's how I will do it next time. 3 hours and it would have been thermo-petrified. If it probes 165 after 40 minutes, so be it.
165-170 in the deep breast and it's coming off. Long live the Thermapen.