I have some books on cast bullets at home and the question of slipping the lands and grooves was answered mathmatically many years ago. I can't remember the mans name but he wrote for the NRA. The fellow's name was E.C. Harrison or something like that but anyway he prooved mathematically that cast lead bullets could not slip the rifleing because of being driven too fast. E. C. Hxxxx did a lot of work to answer some basic questions about cast bullets. Used what we used to call Hollerity cards only sorted them by hand to reach his conclusions etc. Interesting reading.
