To re-shape a ring
Place the ring on a round piece of doweling as far as it will go. Tap gently on the sides of the ring with a mallet, making sure it fits snuggly on the mandrel. Flip the ring over and repeat.
Place the ring on a ring mandrel as far as it will go. Tap gently on the sides of the ring with a mallet, making sure it fits snuggly on the mandrel. Flip the ring over and repeat.