Sift the flour, sugar, salt, baking soda and cream of tartar. Using a fork, mix in the sour cream and then the melted butter until the dough comes together in a ball. If the dough is a little dry, add a small amount of milk.
Divide the dough in half. Put one half on a clean tea towel that has been dusted with flour. Loosely fold the towel around the dough and shape it into a disc about ¾ inch high. Unwrap and cut the dough into 8 triangular pieces. Repeat this process for the other half of the dough.
Cook the individual triangles of dough on a preheated griddle or cast iron pan over medium heat, rotating the scones as needed so that all sides turn a beautiful golden brown. You'll most likely need to cook the scones in batches. If you can muster the self-restraint, allow the scones to cool before eating. Scones are best when allowed to 'dry out'.