If one were to substitute card and fiber for 1-piece plastic wads with the same powder charge and shot weight what would you expect the differences to be for any given load?
Pressure:
Velocity:
Pattern:
Safety note: I have no intention of doing the above without lab verification, but I would like opinions before spending the money for lab tests.
My reasons for making a wad change is to be able to shoot 3/4 oz. target loads in the very tightly choked bores of a 1920 Parker without having to open up the chokes.

Jim