I have read in several books that the A7V had 1 57MM main gun, and 6 or 7 machine guns. I know that Gretchen at first had 8 MGs and no cannon, and normal tanks had 6 MGs and one cannon. Where in the world did the 7 come from? All I can guess is one was stored to be used by the main gun's crew in the front of the vehicle.