Drilling into a bullet is possible, but it is not recommended due to the potential risks and hazards involved.
Bullets are typically made of metal, such as lead or copper, and they are designed to be stable and withstand high pressures when fired from a firearm. If you attempt to drill into a bullet, you could potentially cause the bullet to explode or ignite. The heat generated by the drilling process, combined with the impact of the drill bit, can lead to friction and cause the propellant inside the bullet to ignite, resulting in a dangerous situation.
Additionally, tampering with ammunition or modifying bullets can be illegal in some jurisdictions, as it may violate laws related to firearms or endanger public safety.
If you have a specific reason for wanting to examine the inside of a bullet, it is best to consult with a trained professional, such as a firearms expert or a ballistics specialist, who can provide guidance and ensure safety protocols are followed.