Not really all southern but a lot of our expressions come from the arms production process. Made from scratch comes from scratching the nitrates off the cave wall to make gunpowder. "Lock, stock and barrel" refers to a whole firearm. "Going off half cocked" refers to a flintlock rifle misfiring when the hammer is in the intermediate position. "Couldn't hit the broad side of a barn" originated with musket practice. Our system of gauge measurements (10 gauge, 12 gauge, etc.) refers to the number of musket balls of a certain size that add up to a pound. "Keep your powder dry" is not from a Maybelline commercial.