I think where some of these go wrong is not giving a location. IL that to me would be a 2 1/2 - 3 1/2. Other areas it could be 5 1/2 They get tougher to judge as the rut starts kicking in and winter looms.
I am guessing 3 1/2 , his belly turns up at the rear leg and looks to have a short muzzle. He might look bigger because he is bulked up for the rut.