by johnurckfitz » August 22nd, 2014, 8:50 pm
A number of years ago, the factory rep., told me that Pyrodex, will loose its power, if stored a year or more. I took a half can of powder, and a new unopened can to the range. The new powder went bang, with authority, the year old powder went off. Much less recoil, muzzle report. I would think that 777 would act similar.