Gangplank Probabilty of Ult

Ok, I'm curious about this, is it possible for someone standing within a gangplank ult to take no damage what so ever? Or is the game programmed in such a way that even if the ult is random their is a minimum amount of damage the target will take?

the radius of his ult is 600 while the shots fired have a radius of 150, their is in total 25 shots fired. If someone was to stand completely dead center of the ult without doing anything will the ult guarantee at least one shot hits, or is it "highly likely" for a shot to hit?

so if we wrote the ult in terms of minimum damage to maximum damage would it be 0 to some number or would it be base damage to max damage?