I would think the best way to go is with loose powder pyrodex select 90 grains would be a good start and around 120 loose would be max.Triple 777 also a good choice
As far as sabot I would recommend percision sabot QT40' s in 235 grain flat shooting bullet and a high BC.Another good choice is the hornady sst 300 grain sabot but for some reason they are dhard to load in some barrels this is some reviews on that sabot.
The first step is to clean the m/l real well ,leave no oils in the barrel don' t waste your money on borebutter,next you will need a measure tube for loose powder,209 primers of your choice,clean patches bullet starter,cleaning jag,patch jag, and water in a bottle to spit patch between shot or spit on the patch
Next snap off a couple of 209 primer to remove any oil left in the barrel measure your charge dump the charge next the sabot bullet started with the ball starter then pushed all the way down with the ramrod A little pressure applyied to seat the bullet over the powder ,prime it you are ready to go. after the shot spit patch the barrel flip the patch you are ready to go again clean betwwen shots you should never have ant problem no solvents in betwwen shot