A bullet is made up of what substance?

To determine what substance a bullet is made up of, you can consider the commonly used materials in bullet manufacturing.

Most bullets are typically made up of a combination of several materials:

1. Projectile: The actual bullet that is fired from a firearm is often made of lead or a lead alloy. Lead is commonly used due to its density, which helps provide the desired ballistic performance.

2. Jacket: The bullet's jacket is the outer layer that covers the lead core and provides structural support. It is usually made of copper or a copper alloy. The jacket helps improve accuracy and prevents the barrel of the firearm from fouling or excessive wear.

3. Primer: The primer is a small metal cup located at the base of the bullet cartridge. It contains a volatile mixture that ignites upon impact or when struck by the firing pin, initiating the firing sequence.

4. Cartridge Case: The cartridge case holds the bullet, powder, and primer together. It is commonly made of brass, which is a durable and corrosion-resistant material.

So, a bullet is primarily composed of a lead or lead alloy projectile, enclosed in a copper or copper-alloy jacket, within a brass cartridge case.