Moses;
One other reason has occurred to me & that is the effect of mercuric primers on brass. Mercury makes brass brittle. This was a problem with early rifle reloading with smokeless. It seems the black powder fouling somewhat absorbed the Mercury from the primers, plus cases loaded with black were normally washed after use. There was a problem with case separation when loading smokeless until non-Mercuric primers were developed. I don't recall now the date this occurred but it was much earlier than Non-Corrosive priming as I recall. This could well have been another reason, though it was truly more primer than powder related, but the one affected the other.
