Did this about 5 years ago. I dumped about a 1/2 lb of imr 7828 into about a 1/2 lb of H4350. I cursed called myself stupid names was really pissed off. Learned a valuable lesson and stored my powder somewhere other than on the loading bench, then dumped the appx lb of powder on a paver brick in the front yard and lit it up after dark, it burns bright!
It's hell eatin em live