never put any kind of lube on a sabot... When a plastic sabot is lubed it will cause the sabot to skip over the rifling there by effecting the spin in the barrel. This will cause inconsistant spin of the sabot and effect your accuracy. Actually we want the sabot to expand from the powder explosion and then engage the rifling in the barrel. The one thing I do before loading a sabot, and you might try this if you like is, I might wet the plastic a little with my mouth just enough to slide it down, knowing that the moisture amount is so small it will wear off on the inside of the bore and dry off by itself prior to shooting.

If the projectile your loading is so tight that it is almost impossible to load, then you should consider looking into a different projectile or sabot make. Granted a little tight is alright. What many do is load a sabot that they get their best accuracy from. then they have a second projectile, whether it is a conical, ball-et or different sabot make that although might not be their best accurate load, can still be loaded fast as a back up shot....