I recall a discussion of the 728 I had with several individuals who would have loved to get their hands on one of those, with 28" barrels. None of us could remember ever having seen one with barrels longer than 26". Ever since, I've looked at the specs every time I see one advertised, and still haven't seen one with barrels over 26". Per the Scott records in the Crawford and Whatley book, there were just over 200 each, 728's and 720's, produced.