I recently shot some 25 yard patterns with my Lancaster SLE, which is choked .007 in both barrels. Mid-80% patterns with both a Kent Gamebore Pure Gold (paper case, fiber wad) and a particularly tight-patterning reload in a once-fired Gold Medal hull, plastic wad.

What I've also found is that different shells can result in a significant variation in pattern %--and I'm talking all modern shells with plastic wads. Generally speaking, when I've patterned top of the line target loads (STS, AA, etc), I get higher % results than with less expensive loads, even if they have plastic wads. Difference in shot hardness, maybe? Not sure, but something's going on there.