Unfortunately, I'm afraid caps may be following the primers lead and we may be forced to use whatever we're lucky enough to find. Usually, this time of year I make a round to all the nearby Wallworlds and check for red-tagged muzzle loader items(especially caps). This year, out of 5 stores, I found 2 tins of Win Mags, nothing else. I've used more CCI over the years but I'm just finishing up a few tins of Rem's that I got red-tagged last year....they worked well for me and seemed to pop off the nipple a little easier than usual(although that probably has more to do with the nipple than the cap).
Walt