Much depends on the bullet and the grease groove or grooves. Modern designs have very small grease grooves as smokeless powder residue needs no 'softeners', while BP fouling does. Grease grooves, if designed for black powder loadings of old, are usually similar to the old BP bullet designs, with deep and square grooves to hold lots of lube.
Stiffness of the lube on any particular day will also have an effect in how well it is working. What works up here in 50% humidity and 70 degree temps, might be a good lube for 100 degree or 40 degree weather - it might be too soft or too hard.
The fouling of black powder adds another demand on a bullet's lubrication needs.