Has an AFL game ever ended 78-46?
Exactly once. On June 24, 1961, Hawthorn beat Carlton 78-46, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 78-46 in league history.
That makes 78-46 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 79-46 has happened 3 times and 78-47 has happened 4 times.