Welcome to the madness...
I am thinking about trying maxiballs or another conical.
Have you tried other sabots? Maybe a thinner walled sabot? Different colored sabots indicate a different design/size(as in wall thickness) of sabot.
If you are satisfied with the bullet you are shooting, you can order bullets from Hornady separate from the sabots.
Then you can order sabots for those bullets from MMP(Muzzleload Magnum Products). Google mmpsabots.com
or call them to get advice on an easier loading sabot. Sabot dimensions are on their website but when calling MMP they are very helpful,easy to deal with.
FWIW...if you order your bullets and sabots separately and order say 100 of each, you will cut your shooting cost down considerable. It's amazing what companies are charging for putting the bullet and sabot together in a pretty little package of 15-20 each when you can order 100rds of each(minus the pretty package) separately for about the same cost.