Effectively, not much past 100 yards with a sabot slug and a
rifled barrel, i'd opt for something with a higher velocity like
the Hornady SST, Remington Accutip, or the Brenneke Black Magic. I
will actually be testing this in about a week on a northern Maine
bull with my H&R Ultra Slug Hunter Deluxe, Redfield Revenge
2x7, and I'm pretty sure i'll be using the SST's since my gun seems
to be quite fond of them! Good Luck and safe hunting!