With any of the short cartridge lever guns it’s a good idea to use as large a diameter cast pill that will still chamber. The 45LC chambers (and others) can be a bit generous and using a large diameter cast pill that takes up that space helps to centralise the cartridge to the bore and assist in greater accuracy.
With cut rifle vs microgroove barrels the main issue is using cast. Microgroove barrels have multiple shallow grooves and often larger groove diameter dimensions. This is not a problem for jacketed bullets but for cast to work well they need to be larger than the groove diameter. Bearing in mind what I referred to in first paragraph, it makes to use as large a diameter cast pill that will chamber and feed. It sorts out two problems. Once you work your way through this accuracy will be as good or better than jacketed pills. I have Marlins with microgroove barrels in 45/70 and 35 Rem and they are very accurate with cast bullets.
