First I am not worried about the pressure caused by blackpowder vs smokeless. My concern was if I change the type of hull or type of primer can I expect to have different pressures. Some hulls are more constrictive because they have thicker plastic and are constructed differently and primers are all over the place in how hot and how long they burn. It makes a significant difference with smokeless powders but I'm not sure about black powder.
The plactic cup I use in my loads is just that, a cup. It is used to form better patterning, similar to a paper cup that some use. With the way I reload there is no plactic build up in the barrels as the plastic is buffered from the powder by 1/2" of fiber wad.
And for cleaning, I would clean my guns regardless of whether I use blackpowder or smokeless. I really don't find one more cumbersome than the other. If cleaning the blackpowder takes slightly more time all it means is I get to fondle a 100+ year old gun a little longer :>)
