I don't and never have used fillers, except once.. IMO just another step not needed same as using grease on top of ball. Load powder, felt wad, ball, cap and fire. I never use squeaky loads in my cappers, nor magnum over powdered loads that do nothing but make unneeded fire and spew unburned powder out the muzzle. 18-20 grains in 36, 28-30 grains in models such as 1860 Army, 42 grains in Dragoons, 48-50 in Walker, 40-42 in ROA. Not overpowering loads, all accurate, easy shootin loadings. Tried filler once in 6 rds out of a Dragoon, just another flask to drag around/hang around my neck, fill a shootin bag. Enough of a process shooting a capper without another step, same with worthless grease over balls which does nothing but make a greasy mess after 1st if not 2nd shot.