The calculations are right IMO on both the yield for a bone in buttt (50% yield) and boneless (60%) however a 4 oz serving is light for those with a hungry appetite... take into consideration side-dished, size/weight of the bun its served on (if shredded) and if slaw/sauce are all mixed in... I catered a gig last week where 4 oz was not enough and 6 was more like the amount req'd. This was served on a small bun with slaw.
Brian
House of Q