This is probably very good advice for Pyro and BP. I am using t-7 and get a bit of a 'crud ring' so I swab after every shot, down to the breach. My patches are lightly oiled with avocado oil and and when I pull the rod out, I do it quickly so it pops like a cork coming out of the muzzle. I get the worst of it with the 1st pass and then flip the patch for the fast pull. This suction does a good job of clearing the nipple and flash channel of the crud that oldramrod is talking about. If you are not swabbing, follow his advice. When you do swab, try what I have mentioned.When swabbing between shots try to keep the ramrod from going all of the way to the bottom. It will push fouling down and plug the flash channel, Both of my boy's CVA,s have this problem. Keeping the ramrod from bottoming out solves the problem.Also the stock CVA nipples are soft and will Flatten out at the top. You want a sharp edge. Since the nipples are soft yopu can easily "sharpen " them by putting them in a drill chuck and turning them against a tool stone.
I also swab after every shot for the consistency of a lightly lubed barrel I will have when hunting.
I mentioned in another thread that the Traditions metric replacement nipples have a smaller cap oriface [not the flash hole] than what comes from the factory. The O.D. is the same so I bore mine out to factory spec. to get more flame through the flash hole. This could help you as well if you are using those nipples. As mentioned , those nipples are soft so keep an eye on them for deformation. Also watch for flash hole erosion. When it gets too large you will end up on half cock after a shot. Or, if you're a dummy like me, it will get to full cock before you notice. I watch more carefully now. Good luck. SW