Stephen, thanks for shining your analytical light on post 1954 Rules of proof. The input from Dr. Drew ,his connections (Vic), the source materials he found which are depicted are invaluable. Brent's conversation with Tom Armbrust was also noteworthy as to the difference in pressure readings depending on length of hull vs. chamber length of pressure testing barrel and the operation of Boyle's law. Borderbill's sharing of his test sheets are a great starting point for reloaders. The grey area for me remaining (more hand-wringing) are the recommended service pressures for the pre-1954 guns which in the 1930s went from 3/4 to 7/8 oz. service load recommendations. Gil