.
An equation for proof pressure per the Oktober 30th, 1897 Belgian Decree/May 10th, 1898 note the Proof Charges were to attain a pressure of 80% over the maximum service pressure and the resulting mark was the Rampant Lion over the Max load stamp.
Belgian Decree of November 18th, 1903 with the >>Unique<< Powder for the 4th proof was not to exceed 875 kg/cm^2 or 13k lbs/in^2.
The Pressure for the 5th Proof Effort was not to exceed 750 kg/cm^2 or 11k lbs/in^2.
A little tid-bit more of info from another source gives that early semi-smokeless powders achieved a vast array of pressures between 6k to 10k PSI. So it was the goal of the Oktober 30th, 1897 Belgian Decree to adopt a powder to achieve a proof pressure of 80% over the max service pressure but that value must exceed 8.8k PSI.
Seems the Brits are pulling & driving the Proof Ox-Cart & all others are basing their Proof Rules on the British Scales. The Brit's March 10th, 1896 Rules Update directed that Choke Bores tubes to be proved w/ Nitro Powder to be acknowledged to the Proof Compagnies in writing by the sender and that the tubes would also be subjected to a Proof w Curtis & Harvey's No. TS2, or a powder that was equal in all respects. Curtis & Harvey's No. TS2 was a fine grained black powder. The Proof Compagnies decided that with the every changing variety of new fangled powders in addition to the primary Schultze or E.C.(Explosive Company) that the sender could very well choose another powder but the powder must achieve a stress of 80% over the Service Charge and under 100% of the Service Charge. Scale No. 6 was the gospel and everything else based on it. Then the Service Charge Powder & associated Shot weight were to be marked on the Barrels:
MaXm - SCH. ?? Grains & Shot ?? OZ.
Then one finds the Germans draggin' their feet behind the rest.
Hochachtungsvoll,
Raimey
rse
