I've seen "paper patch" mentioned in some of my reading, but thought maybe it was just for the black powder loads. Is that required with smokeless? I know Hodgdon doesn't mention anything about it on their load data site. Is it just for filler since it's such a large case?
You can use paper patches on cast and swaged bullets. For hunting loads it's pretty good 'cause it provides a wear surface between the gooshy lead and the barrel. A generous slope into the barrel works best and so old military rifles with the throats eroded away can be really good... just load them with smokeless and find a load that works.