I had very mixed results chronographing loads with the 12 bore hard waxed cards from BP which Gil mentioned. I was using them without lube in RMC brass shells with 1.25 lead shot in four different loadings: 27.5 gr Longshot, 28.0 Longshot, and 35 gr. Blue Dot, all with reclaimed shot, and on another occasion again with 27.5 gr. Longshot but this time with new lead shot. Five shots each. The three loads with reclaimed shot yielded speeds all over the place, between 472-1011; 773-1059; and 781-1171 respectively. With that much variance, I don’t think the averages meant much.
However, on the second day and using new lead shot over 27.5 gr. Longshot, I got much more consistent speeds of 1101-1171 fps, with a mean of 1139. I would not have thought the shot quality would have made any difference but perhaps someone can set me straight. Otherwise, I have no explanation for the extreme inconsistency with these wads and I never used them again.
