Back in the late eighties I bought a used possibles bag at Charlies Gun Shop in Albuquerque NM. Evidently an ol skinner went under or maybe couldn't do his thing anymore. Anyway, the bag had some handmade stuff in it including a antler piece that was made to hold caps. Had a carved wooden stopper and you just shake out a cap at a time.
I don't shoot caps much anymore, mainly flints, but I took out one of my cap pistols awhile back and just for the heck of it shook out one of those old remington caps to see if they were still any good. Fired right away. As did the second and third.
Got a good deal on a box of ten of the CCI's awhile back and have been using them, and they preform well for me too. Don't know if it really makes much of a difference.