Lyman's books cover them - I'll look them up if you'd like & PM. Slower powders will be on the menue, I'd guess - prebably Blue Dot, SR4756, Herco, Unique, Longshot(Hodgdon might have some slug data). I suspect Lyman will list herco, SR4756 and Blue Dot - maybe H or IMR4227 - maybe not.

personally, I am against sabots and will not use them, except perhaps the Lyman Sabots which shoot large diameter bullets, not undersized ones. I cannot see using a 12 bore and shooting .50 cal bullets, or even .58 cal. It's a 12 and I want the advantage of shooting a 12 bore projectile.

A 20 bore might use a .59 or maybe .58 I suspect, in the Lyman slug, which 'just' fits inside a normal shot cup. That I could use, but not a .45 or .50 cal. I've got rifles that small for shooting those sizes.