Nice work!
I've always suspected that the problem with the 1-48 twist was related to modern guns with shallow rifling more than the twist itself. Somewhere I think I read that original Hawkens often had 1-48.
Another apparent myth is that you need a 1-28" or so to shoot sabot loads. I've gotten decent, if not sterling accuracy with sabots and 250gr bullets in a couple of older TC rifles; good enough for woods hunting for a guy that started hunting with smoothbore slug guns, anyway.
