ok then looking for some opinions

I have a lovely pietta 1858 NMA stainless target model

Im fairly new to black powder and it shows on the target sheets

shooting one handed at 25yards I can just about keep the 6 shots on an A4 sheet of paper

anyway I currently have a regime of 26grains of pyrodex P a yellow felt wad and then the .454 ball 160gr?

anyway I have noted that some BP shooters will put grease in the end of the chambers over the ball,

is this just to protect the barrel?, or does it somehow improve the travel of the ball down the barrel??

so do you use grease or dry??

and why please??