doublegunshop.com - home Forums Thread Like Summary - French Powder Strength & Proof Pressures

Despite unsuccessfully searching for Pete Mikalajunas' thread from long ago, I think I've figured out the French l’Administration des Poudres et Salpêtres sporting powder strengths
Semi-smokeless Poudre J - 15.8 grains/dram = 47.4 grains = 3 Dr. Eq.
Semi-smokeless Poudre M - 12.76 grains/dram = 38.3 grains = 3 Dr. Eq.
Poudre T Pyroxylée Sans Fumé (introduced in 1899) - 11.5 grains/dram = 34.5 grains = 3 Dr. Eq.

For comparison

42 grain = 3 Dram Equivalent Bulk Powders
“E.C.” No. 1
“Schultze”
DuPont Bulk (40 gr.)
Curtis & Harvey “Amberite” (40 gr. on introduction - later 42 gr.)
Sporting Smokeless Powder Syn., Ltd “Cannonite Shot-gun”
Smokeless Powder Co. “S.S.” (Smokeless Shot-gun) (43 grains)
Cooppal & Co. “Cooppal’s No. 1”
Louis Muller & Cie S.A. “Mullerite No. 1”
United States Smokeless Powder Co. “Gold Dust”
Dynamit Nobel’s Troisdorf Powder Co. “Troisdorf” (41.5 grains)
American Wood Powder
“J.B.” Powder

36 Grain = 3 Dram Equivalent Bulk Powders
New DuPont Bulk (37 grains)
Laflin & Rand Bulk (37 grains)
Hazard Powder Co. “Blue Ribbon” (37 grains)
“E.C.” No. 2 (Improved)
“New Schultze”

33 Grain = 3 Dram Equivalent Bulk Powders
“New E.C. (Improved) No. 3” (introduced in U.S. in 1904)
Curtis’s & Harvey “Diamond Smokeless” (1903)
Red Star (New Explosives Co., Stowmarket)
Walsrode Smokeless & Waterproof Gun Powder Co. “Walsrode Gray”
Louis Muller & Cie S.A. “Mullerite No. 2”
Nobel’s Explosive Co. “Empire”
“Cooppal’s No. 2” (30 grains = 3 Dr. Eq.)

French proof pressures follow

https://books.google.com/books?id=_IVMAAAAYAAJ&pg=PA933&lpg
Charges yielding equal velocities; ounce not specified
Nobel's Ballistite 1.8 gram = (about) 28 grains = 3 1/2 Dr. Eq. with pressure 400 kg/cm2 = 5,689 psi + 10 - 14%
Mullerite (No. 2) 2.3 gram = 35.5 grains = 3 1/4 Dr. Eq. with pressure 550 kg/cm2 = 7,823 psi
Poudre T 2.5 gram = 38.6 grains = 3 1/3 Dr. Eq. with pressure 600 kg/cm2 = 8,534 psi

That Ballistite pressure is highly suspect

From the 1928 edition of “Smokeless Shotgun Powders” by Wallace Coxe, ballistic engineer of the Burnside Laboratory of the E.I. du Pont de Nemours & Co.
12g 1 1/4 oz. 3 1/2 Dram Eq. + 10 - 14%
DuPont Bulk smokeless - 11,700 psi
Schultze Bulk smokeless - 11,800 psi
28 grains of Ballistite Dense smokeless - 12,600 psi
40 grains of DuPont Oval Progressive Burning powder - 9,400 psi