On my brisket, I aimed for 1 hour per pound when at 250F. i didn't even look at it before the end of the time.
I jabbed the probe in the middle of the side of the flat. It had the soft-as-butter texture. I checked the temp, in my case 195F.
I had it wrapped in a cooler for 2 hours, for the last hour with a dozen ears of smoked corn.
It was tender and moist.
Now you got me thinking I need to do another one this weekend.
Just to verify my results.
OTS, 18 1/2 WSM (Betty), iQue110, 30" MES