Below is what a well recognized black powder manufacturing expert with the screen name "mad monk" posted on ALR. From what he says it's pretty clear that 777 resulted from changing the formula of Pyrodex which ended up increasing its shelf life. And he distinguishes those 2 powders apart from the sugar based powders which he says belong to 2 groups, the AA powders and fruit sugar powder.
Originally Posted by mad monk Reply #19
Pyrodex uses elemental sulfur in with the potassium perchlorate, potassium nitrate and a bit of charcoal. If you look in: The Chemistry of Powder & explosives by Tenny L. Davis, in the section on primer compositions you see a warning where a chlorate or perchlorate muist never be used with elemental sulfur. That with the addition of moisture you will get a "self-souring" action in the powder. The reaction makes the composition unreliable. At first the composition becomes erratic in its behavior. Then becomes weak and then finally stops working completely.
I was impressed with Hodgdon's 777 powder. A change in formulation that should give a very long shelf-life with no deterioration in performance during storage.
http://americanlongrifles.org/forum/...?topic=3986.15
Originally Posted by mad monk Reply #23
The main ingredient used in Pyrodex and in 777 is unique to those powders and had not been used in the past in propellant powders.
The same is true for the use of ascorbic acid in powders. Another one sort of unique to the present.
The only one with any straight historical background was GOEX's now defunct Clear Shot powder that was based on the combination of fruit sugar and potassium nitrate. It has history back into the 19th century.
http://americanlongrifles.org/forum/...?topic=3986.15