Answer: Individual
Step-by-step explanation:
Class characteristics are those features which can be common in objects constructed from the same machine. Like the shape and size. Individual characteristics are those features which can be found on the object due to it's wear and use. These can be random tool marks, like scratches, scrapes and lines.
According to the given situation, the bullet and gun are expected to have tool marks which could have produced by wear and use. Therefore, this information provide individual type of evidence.