Timeframe

At that temp, you should be good at about 12 hours. I might would give myself 14 hours to be on the safe side. You can always hold them over in a cooler, wrapped in towels or a blanket.

At 275*, and panning / wrapping them when they get the color I like, mine usually take about an hour a pound. Always best to add extra time for resting and what if's...

Jeez, At 275-300 with wrapping I would've guessed maybe 6-8 hours, maybe I'm losing my touch :noidea:

I would start a little earlier than you think you need to. Butts are super forgiving and will keep hot in a cooler for hours if you finish early. Also, if they don't seem to be finishing fast enough, just up your temps. Esp after wrapping you can go 350-400 with no ill effects. I've cooked unwrapped butts at 350 and had them finish in under 5 hours, just as good as an all day cook :thumb: