That makes more sense now. That's a pretty small butt. You can use a temp probe to give yourself an idea on how the meat is progressing but once a butt hits 180F (for me anyway) I start checking the bone wiggle at about every 5 degree increment. After a while it will be like riding a bike. Cheers!!!
If Homebrew & BBQ aren't the answer, then you're askin' the wrong questions... Cheers!!!