Has an AFL game ever ended 77-39?
Exactly once. On July 22, 1911, Melbourne beat St Kilda 77-39, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 77-39 in league history.
That makes 77-39 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 78-39 has happened 3 times and 77-40 has happened 2 times.