doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Smokeless powder question

In looking at standard and proof load data from the turn of the 20th century, I find references to bulk and dense smokeless powders and a corresponding difference in maximum chamber pressures. What I can�t seem to find is the difference between these two powder types. Can anyone shed some insight?
Thanks,
Dave Myrick

Some of the early smokeless powders were loaded on a volume for volume basis like black powder. The dense were loaded at a much less volume, by weight. So wadding has to be different and loads were much different. Also there were a couple semi smokeless powders in this time frame. Black powder did not suddenly stop. It was replaced over a couple decades. Several powders came and went during that period.

More than you probably want to know here
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/preview

Higher chamber pressures with Dense smokeless compared to Bulk, and much higher compared to DuPont Oval



The only one that's still around is "Infallible", which with a slight change in formulation became Unique

Alliant data for 1 1/8 @ 1200fps 12g.
Alliant e3 - 17.2 grains = 10,950 psi
Red Dot - 18.3 gr = 10,300 psi
Green Dot - 21 gr = 8900 psi
Unique - 22 grains = 8900 psi
Green Dot and Unique pressure curves are indistinguishable.

Am I to gather that the reference to bulk and dense was in the way it was measured and not the powder itself? So for instance DuPont could be considered both depending on if it was measured by volume as opposed to weight?

Dave Myrick

That is not correct Dave.

Bulk powders could be measured to the same volume (Dram/drachm = the proper capacity to measure one-sixteenth of an ounce by weight of black powder), but loading to weight in grains later became the standard.

Henry Sharp, The Gun: Afield & Afloat, 1904
�Sportsmen are now in possession of two definite types of smokeless powder, the so-called bulk powder and the newer concentrated or condensed powder. The first is designed to occupy the same space as black powder in the cartridge-case, although only weighing about half as much.�

1902 Sears catalog "...dense nitro powder should be weighed using an apothecary's scale and not measured."

Thanks for clearing that up for me. It is much appreciated. Both were formulations of smokeless powders but they were different formulations similar in concept to for instance red dot and green dot. Both made by the maker but with different performance characteristics and corresponding charges.

Dave

Bu7lk powders were often characterized by the grains weight of a 3 dram "Volume" measure. Thus original Schultz bulk shotgun smokeless was called a 42 grain power as a three dram black powder volume weighed 42 grains (3 drams of black weigned 82 grains). Neither were normally weighed but were simply dipped with a measure marked in drams. 1 dram was calculated at .115 cubic inches. Later EC bulk weighed 33 grains for the same 3 dram measure so was called a 33 grain powder.

As I recall from an article in the Rifleman many years ago Infallible & Unique had identical chemical formulations. They were round discs which I don't recall their diameter but were the same there. The Infallible discs were 3mm thick while those for Unique were thickened slightly to 3�mm. Infallible thus would be slightly easier to ignite but would give slightly higher pressure for the same weight charge. In the card & felt/fiber wad days Unique with a 1oz load in 12 gauge required a very heavy wad pressure (on the order of 100 lbs) to ensure adequate ballistics.