WHAT DOES REMINGTON PRIMERS 7 1/2 MEAN?

Even though we (me?) sometimes poke pleasurable and jabs at Hodgdon/IMR for stating "just use another men data for The brand new Rainbow shotgun powders", I would post that was most likely a pretty good final decision by them to complete/say that.Probably it's something to complete Together with the angled firing pins employed by more than/below sh