Harvester BLACK crushed rib sabots are normally for the .452 diameter bullet. MMP also makes some thinner sabots. The red sabots can be in .452. I purchased a bunch of Barnes bullets and all of them came with red sabots. They were .452.

Green sabots are generally for the .430 or the .44 caliber .430 bullet. Did you swab between shots when you discovered it was hard to get the second sabot down the bore?