I have never made my own BP but have shot some homemade and with no issues. When I was heavy into BuckSkinning many moons ago, we use to make a lot of our own stuff and have to admit it was enjoyable. As for caps, I have made my own but not familiar with Prime-All. I use to have a tap-a-cap tool.
I have seen more than one ratio listing. There is a process called "Corning", when making BP not sure how important it is but you may want to look into this...
BE Safe !!!