Sift flour, baking powder, salt, baking soda, and sugar into a large bowl.
Drop in 3 heaping forkfuls of shortening and blend into the flour mixture with the fork (or pastry blender) until it becomes coarse crumbs.
Add buttermilk all at once and stir just until the dry ingredients are moistened, or you have a shaggy dough. Turn onto a lightly floured surface and knead 4 to 5 times, patting into a disc. (DO NOT over knead.)
Roll to about 1/2 inch thick. Cut with a biscuit cutter dipped in flour and place onto a baking sheet. Brush gently with melted butter and sprinkle with coarse ground black pepper.
Bake for 10 to 12 minutes. Remove from oven and brush again with melted butter.