Preheat the oven to 400 degrees F (205 degrees C).
Bake pie crust in the preheated oven until partially baked, about 5 minutes. Set aside.
Adjust oven temperature to 325 degrees F (165 degrees C).
Combine sugar, milk, melted butter, flour, vanilla, and nutmeg in a large bowl; mix well. Beat in eggs until well blended. Pour filling into partially baked pie shell.
Bake in the preheated oven until a knife inserted in the center comes out clean and custard is set, 45 to 55 minutes.
