LBT made a two-cavity mold for me with one cavity cut without a lube groove. It was intended for sabot use. As it turned out, both the grooved and un-grooved bullets shot well in sabots, but only the grooved bullet was useful in 45-70 cartridges.
"Mould" is often considered a British spelling, while "mold" is American. Both spellings are used so often and interchangeably that the distinction is lost.