If you weren't impressed by the Harvesters it may have been either poor quality castings, or the fact that they have cheapened thier carefully developed sabots, which gave awsome performance when they were first developed with the work of Al Marion, who I worked with in developing the bullets. He hand casted all his, and enjoyed precison grouping.
Something i've never figgured out is. Why on earth to the sabot makers all put huge cups or hollow bases on soft plastic cups to gt them to seal, when the two biggest problems they have is too much obturation pressure against the bore, which caused plastic fouling, and when they exit the muzzle the thin cup base flares out like a mushroomed bullet, which produces far from a square bullet base for the gallons of black powder smoke to squirt around and tip the bullet sideways.
If some one of you readers has a lathe at your command, would you try turning the bases flat and putting a slight bevel on the edge of a couple brands of sabots with the big cups. Don't flatten them completely. Just take perhaps half the cup off, so the wad of plastic below the bullet remains quite thick and strong.
If anyone does try this, please let all the readers know. By the way, the easiest way to turn them would be on a mandril which is turned dead true on the lathe. Slide the sabot on, then a metal sleeve over it to clamp the sabots firmly in place full length, except for the base portion that will be machined. Don't remove the mandrel from the lathe to remove the sabots. Just slide the sleeve off and the sabot will come off with it.