This is a pressure-time curve, possibly Hodgdon Clays from
http://www.arizonaammunition.net/ Note the small primer spike then the powder combustion
Courtesy of Neil Winston and similar
www.claytargettesting.com
Pressure - distance curve from "Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics" by Wallace H Coxe; E.I. du Pont de Nemours & Co., 1933 promoting DuPont MX (which sorta became PB)
Pressure - distance curve from the Alliant site
I don't see any evidence of a pressure rise, or interruption of the fall in pressure, when the ejecta "slams"
into the forcing cone
Pictures are nice, but number would be better however
