In a large bowl combine all dry ingredients and mix well. Cut in butter and shortening until its the consistency of wet sand. Add in buttermilk and gently mix careful to not over work dough. Pour out onto floured surface and pat dough together. Fold over several times to create layers. Pat or roll out until about an inch thick and cut biscuits out. Do not twist the cutter because that may seal the sides and biscuits wont rise. Bake on 425° for 15 to 20 mins.