I have often thought that there really isn't a point of collection for our own individual loading data for double rifles, especially Bore rifles and Ball and Shot guns. Collectively this could be useful information for many which can bypass days at the range and add some safety as well. Is there interest in sharing our results?? This can be done with a simple speadsheet to be built upon. Graehme Wrights book is about the best I have seen. If there is another in existence, let me know.
John