British
1896 Rules of Proof
Black and Nitro powder Service and Proof Charge Pressures
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA296&dqUnder the existing Regulations of Proof in England, a “service charge” is specified for every bore, and the compulsory definitive proof is made with double the service charge of proof-house powder and 1 1/3 (times) the service charge of No. 6 shot. Besides the compulsory proof, a supplementary proof with other kinds of powder is permitted, if applied for. Many other charges, both larger and smaller than the officially stated “service charge”, are in constant use.
Note the pressures are expressed as psi by LUP and one must
add 10 - 14% for psi by modern piezo transducer
Curtis & Harvey “T.S.” (Treble Strong) No. 6 (84 grain = 3 Dr. Eq.) was coarse Black Powder somewhat similar (but not equivalent) to Fg.
“T.S.” was developed in 1871 for the .577/450 Boxer-Henry cartridge used in the Martini-Henry rifle. It was a precursor to “R.F.G.2” (Rifled Fine Grain 2) manufactured at the Royal Gunpowder Mills, Essex, adopted in 1873.
C&H “T.S.” No. 4 (82 gr. = 3 Dr. Eq.) medium grain similar to FFg
C&H “T.S.” No. 2 (72 gr. = 3 Dr. Eq.) fine grain similar to FFFg.
Prior to 1925 same as above
12g 2 1/2” and 2 5/8” chambers (bore .710-.740) for a maximum service load of 3 1/4 Dram Eq. with 1 1/4 oz. shot. (1220 fps)
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA296&dq Definitive Proof – 6 1/2 Drams Proof-House Black Powder with 1 2/3 oz. No. 6 shot =
10,100 psi + 10 - 14%Supplementary Nitro Proof with 4 1/2 Drams of C&H No. 2 T.S. powder and 1 2/3 oz. shot = 16,400 psi + 10 - 14%
