If you are using real black powder, and not a substitute, in your Renegade, a #11 percussion cap should be all you need. Remember to wipe the bore of all oils, and snap off a few caps before first loading, to dry out the flash channel. I use # 11 caps in most of my muzzleloaders, but have used musket caps in the past, when I used Pyrodex. I have no ignition problems with # 11, and real black powder. True, as said in the above post, musket caps are easier to handle, if you carry them in your pocket, and need a quick reload in the field. If I had to use a substitute powder, I would give musket caps another look.