Percussion cap failure to fire
Is the most common cause for the failure of a percussion cap to fire the fit of the cap to the nipple? An old CVA side-lock cap and ball rifle seems to have a very tight fit of #11 cap to the nipple, and an occasional failure to detonate the cap, which I suspect isn't seating fully and bottoming onto the nipple. I think that the first blow of the hammer actually pushes the cap fully onto the nipple; I have already pushed it on as hard as I can push with my thumb or finger. The cap seems a little flattened, and always pops the second time. I believe the spring driving the hammer is OK, it seems like (?) a hard and fast hammer fall. The caps are RWS (the only local brand #11's), seem in good shape. If this makes sense, would the fix be polishing the outside diameter of the nipple a bit, to reduce the diameter a thousandth or so and make it easier to bottom the cap?