Mark G, thanks - the also was true when going with less crimp. I believe Mark O. in a previous post had some info about shot hardness effecting pressures. JMHO - lead shot will flatten a bit in the back part of the shot column, acting like the cushion part of the wad. This allows the expanding powder gas to expand more easily, meaning less pressure. Might be all wet with that theory, but there's some reason hard shot raises pressures. The roll crimp issue. Mark had also commented on deep roll crimps raising pressure and I would agree with him.
__________________
Paul Harm
|