You asked the question I answered it.
There are hundreds if not thousands of shooters shooting for fun and competition that load 70 or more grains of blackpowder in winchester,remington and starline cases by the hundreds , and for some reason this internet nonsense whooey about can't fit 70 grs of powder in a modern case persists... And I'm not sure how that manages to happen other than it's perpetuated by folks that don't have any experience doing it.