ANY day shooting is still better than your best day at work.
Well except maybe the day Christmas bonuses are handed out.
My favorite fun load in a 54cal is the 225gr FTX. The sell by the 100 instead of 50 and are mild on the shoulder. You could use either 54x44 of 54x45. I prefer the 54x45 since the Harvester sabot is the one i usually use for my hotter hunting loads. The MMP 54x45 fits tighteer.
BTW the MMP/Barnes 54x50 sabot with a short 300gr like the 50-300gr DeepCurl/GoldDot shoots great and doesn't need much fps to smack the snot out of a deer. I know they work ok in a 1-38. They are really good though in a 1-28 twist. Im not sure how well they would work in a even slower twist.