doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Wall thickness opinion

Since we've wandered off into Francotte proof marks, this might be of interest.
As greybeard observed, the rule establishing the marking of barrel weights (at the time of 3rd proof) and chamber length & diameter (in mm) came into force June 6 1892 FOR OPTIONAL NITRO PROOF.
And 1897 - 1903, the proof house kindly provided the max. service load, based on the powder with which the gun was proved. I've also seen guns proved with Mullerite, "E.C. No. 3", and "New Schultze"; never with the primary competitor DuPont The maker paying for the extra Nitro proof could request the powder used.



A gun imported by William Read (so marked on the rib) It was proved with "E.C. No. 3" which was a 33 grain = 3 Dram Eq. powder; so the max. load was 1 1/8 oz. 3 Dram. NOTE powder & shot in 'American'



A Francotte which WAS Nitro proved for a max. load of 2.72 gram 'Schultze' powder = 42 grains = 3 Dram with 31.5 gram = about 1 1/8 oz. shot
The ACO in the circle is Acier Cockerill-Ougrée, the major Belgian steel maker, equivalent to Krupp or Vickers.
Note again 2 sets of muzzle and bore dimensions



I suspect the proof house gave up as more and more powders, at different strengths, were introduced.

The original “Schultze” & “E.C.” No. 1 Bulk Smokeless were 14 grains/dram
The original DuPont Bulk was 13 1/3 grains/dram
The original Laflin & Rand and Hazard “Blue Ribbon” Bulk were 12 1/3 grains/dram
Advertisements appeared in the later part of 1906 for “New DuPont Smokeless” which was also 12 1/3 grains/dram
“New Schultze”, New “E.C.(Improved) No. 2” Bulk Smokeless were 12 grains/dram.
“E.C. No. 3” was 11 grains/dram or 33 grains = 3 Dr. Eq.
Dense “Ballistite” and “Infallible” were later listed as equivalent at 8 grains/dram.

42 grain = 3 Dram Equivalent Bulk Powders
“E.C.” No. 1
“Schultze”
DuPont Bulk (40 gr.)
Dead Shot
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” (or “Wetteren”) and “Clermonite”
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.)