Howdy
It appears that you have the R&D (Taylors) conversion cylinders?
Anyway, a Big Lube bullet is the way to go. Fill up the case with enough Black Powder so that when you seat the bullet the powder will be compressed by between 1/16" - 1/8". That's all there is to it.
With Pyrodex and Real Black Powder you will be much better off if you use a good Black Powder compatible bullet lube. I use SPG. There are also lots of home made brews. I used to use a 50/50 mixture of Crisco and Beeswax.
If you are using real Black Powder, I find that the cleaner burner the powder, the better the results. 1858 Remingtons are not real great with multiple cylinders full of Black Powder because of the cylinder design. So if you can find it, I recommend Schuetzen powder. It burns a bit cleaner than Goex. Graf sells the same stuff under their own label.
One more thing, if those are R&D cylinders, you have to pull them out to reload every time anyway. Wipe off the front face of the cylinder and the cylinder pin with a damp cloth every time you reload, it will help.