Spring, as Garby states, the woodleigh solids have a steel jacket which makes them harder than softs, which in turn causes pressures to be raised slightly and therefore raises velocity slightly. Ross Seyfried wrote an article in the double gun journal a while ago about this and stated that all you needed to do was to drop you load by 2 grains for the solids and you should get around the same velocity as you do with your softs. This you are already doing so you are on the money. I load my .470's at 89gr for the softs and solids at 87gr and I get the desired results.

wadeb