topshot has a good answertopshot has a good answer on how to separate the slug from the brass. Brass is designed to be reused, which is why reloading exists. Bullets/slugs are designed to be used once. Reusing the brass as long as it still meets expectations is fine.
If you reuse a bullet where the brass was damaged enough to make it unusable, you will be betting your life and others that the bullet was not damaged similarly.
If the bullet you are attempting to save is worth a few cents or tens of dollars, it is import that it work as designed. I searched and could not find anyone suggesting that reusing a bullet was a good idea.
Save a life, don't reuse any parts from a reload failure.
