Around the time of the 1912 Suhl rules was the period when the 9.3X72R was normalized. I think the rules were the reason for the addition of the "R"(Rand). I believe the 9.3X72R Normalized was closer to the dimensions of the 9.3X72R D but that the rim was a little smaller in diameter. I can't say on the thickness but I have read that sometimes only a magazine correction was needed to except the new normalized 9.3X72R.
I don't think the 1st proof changed at all being a triple multiple in black powder of the service load and a double multiple in mass of the service load. It was the 2nd proof where the "semi-smokeless" could be equated to the double multiple in black powder with the projectile load being a 1 1/3 multiple of the service load. It is here the "Crown" over "N" originates and apparently there wasn't much use of the "Crown" over "Nitro" on rifle tubes as the "Crown" over "N" and the "Crown" over "Nitro" were synonymous. I think there would also have been a matching "Crown" over "N" on the watertable. It is also here the type of bullet used was indicated being steel jacket, copper jacket or lead. So it is possible that in this scenario of the 2nd proof that the joined tubes in the finished state could have been rifled. Pre-1911/1912 would have had the supplemental/voluntary stamp of "Crown" over "N", or "F", with the powder weight over the bullet type and I think this proof exposure would have been much later in the process. I haven't any idea as to the "F" for now.
Kind Regards,
Raimey
rse
