Ed: a pressure-distance curve for some new-fangled smokeless powders; 1 1/8 oz @ 1200 fps. Please note that
Unique is the old Infallible Dense Smokeless slightly modified. The curves meet at about 2 1/2"
Pressure-time curve. The Green Dot and Unique curves are the same.
From “Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics” by Wallace H Coxe; E.I. du Pont de Nemours & Co., 1927, promoting DuPont Oval, p.20.
Charge was 3 Dr. Eq. and
1 1/4 oz.
Ballistite maximum pressure at 1” was 4.9 Long Tons = 10,976 psi
Schultze at 1 3/4” was 4.5 Long Tons = 10,080 psi
DuPont Bulk at 1 2/3” was 4.1 Long Tons = 9,184 psi
FFFg at 1 1/2” was 3.8 Long Tons = 8,512 psi
DuPont Oval at 2” was 3.5 Long Tons = 7,840 psi
+ 10-14% to reproduced modern transducer numbers so Ballistite was probably
> 12,500 psi
Dense Ballistite was slightly slower than Red Dot and e3; the old Bulk Smokeless more so with a lower peak pressure; "progressive burning" Oval much more so.
01-28-2020, 07:23 PM
Hybrid Mode