From what I have seen in my limited years (10 or so) doing this, the nipple is the item that usually changes the most often. I have all my percussion rifles using the same brand of nipple and a few years ago when I had some extra $$$$ I bought 3 dozen from some one? Took all the existing ones out and put in the new ones. There are some web pages somewhere that show the flame out of various nipples with various caps although since with most side locks the flame has to turn 90 degrees sooooooo? My two under hammers have much better ignition, but both have non set triggers.