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

The pressure figures at various distances from the breech shown above are significantly different from those shown in the Dupont chart that dates from 1933. All 4 powders (3 types of Dupont smokeless plus FFFg black) produced pressures reading between 3500-4000 at 10 inches. That's measuring in LUP, so converted to psi, the readings would all be over 4000. Sherman Bell's tests, reported in Doublegun Journal, gave readings ranging from about 1500 to just under 2000 psi at 12 inches. Per those figures, while pressure does indeed drop rapidly, it doesn't drop nearly as rapidly as the figures posted above would indicate.

Here's a curve, possibly Hodgdon Clays from http://www.arizonaammunition.net/



Note the powder is FFg. FFFg is similar to Curtis & Harvey No. 2 with a curve much like dense smokeless. From Sporting Guns and Gunpowders: Comprising a Selection from Reports of Experiments, and Other Articles Published in the "Field" Newspaper, Relative to Firearms and Explosives, Volumes 1-2, 1897



The Ballistite curve would be similar to modern fast powders like Red Dot



The choice of 32 grains of Ballistite is confusing, as 24 grains is the published load for a 3 Dram equivalent; 26 grains for 3 1/4 Dram.
Alfred Nobel's 'Ballistite' was introduced in 1887, patented in 1888, then �Sporting Ballistite� (for shotgun shells) was patented in 1889, but not released to the trade by Nobel�s Explosive Co. until 1895. The published summary of the Trial states �Ballistite� rather than �Sporting Ballistite�.

For the non-deep thinkin' MU grads amongst us, pressures are pretty low after 18" no matter what powder is used

That's something even the liberal arts majors can grasp, Doc Drew!

The new hotrod, non techno, underwater basket weaving equivalent is Industrial Distribution, AKA Warehouse Coodinata.

I'll never forget my brother majoring in Industrial Technology.
I asked him what that was and he told me, (NO JOKE), it's an engineering degree without the math. SAY WHAT?
My daughter is in her first DifEQ class at A&M this semester. Definitely a head pounder. She didn't see the humor in the "without the math" statement. I love pushing her buttons.

Definitely worth a chuckle.