Someone posted this on another forum and thought I'd share it here. Not sure if this is a dupe (from 2007) but it has some really interesting information and photos about smokeless powder over the last ~100 years. I didn't realize how old some of our smokeless powders really are - Unique and Bullseye for instance.
70 page PDF:
http://www.castpics.net/subsite2/GeneralReference/L&R-Smokeless.pdf
70 page PDF:
http://www.castpics.net/subsite2/GeneralReference/L&R-Smokeless.pdf