Please can anyone advise a reliable and legal UK supplier of black powder? My purpose is to use it in ejection charges for a dual deployment rocket. I'm assuming there are suppliers as I've seen trials and actual charges going off at EARS. Can't find a supplier on the web however. Also, would you advise the best grade of powder to use. I don't know much about the grading and the differences between coarse and fine. The advice I've read so far ranges from FFFFG down to breaking open a fire work! I can guess the difference but would like to know a bit more of the science behind powder types before using some. Thanks, SO.