I've had great luck reloading Gun Club 12's. Haven't fooled with Estate 12's, but I've reloaded a bunch of 28's, and am now reloading 20's. You will get occasional hull separation with the 28's (don't know about the 20's yet), leaving just the brass and a little bit of plastic. Everything's always gone down range when that's happened to me, and there isn't much of a safety issue with a double as long as you check the bore when that happens. But you might not want to use Estate 28ga reloads in an autoloader or pump, if you're shooting doubles or something like that. Federal 28ga hulls do the same thing, however, and I've had people tell me Winchesters do as well, although I've never had it happen with a Winchester.
