I don't have a dog in this fight, but proof tables were published because they were regulatory( actually statutory) for proofing the barrels, and show loads greatly in excess of any duty load. It is the same with the projectile weight for proofing. The "duty" or "regulation" load was entirely different and would have been determined by the cartridge's designer, not the government . This load would have been half or less than the proof load. Likewise bullet diameter and weight would vary, according to design. Two rifles of the same nominal caliber might use differing diameter bullets, depending on whether a "paper case" or "brass case" was intended to be used. Black Powder Express cartridges generally used lighter than normal bullets to achieve higher velocities. It was Nitro Express cartridges that achieved higher velocities with heavier bullets by generating higher pressures with cordite and similar propellants.
Mike
