Sabot Seating

[Cossack]

New to muzzleloading. Been working up loads for my Encore 50 using loose T/7 and pellets. Seating bullets with sabots is a real chore. I really have to push on the rod to get it done; doubt I could get it done in time for a follow up shot.
Here's what I am doing: Clean barrel with patch soaked in water/Simple Green mix. Dry with two patches. Reload.
Powerbelts seat fairly easily. But 245 gr Barnes Expander MX and 300 gr Hornady SST ML's are very hard to push down. Nearly have to stand on the rod to get them down.

What should I change? And advice is appreciated.