Which component ignites the gunpowder inside a cartridge?

• A. Bullet
• B. Powder
• C. Headstamp
• D. Primer

Answer: (D)

Ignition inside a cartridge is started by the primer. The primer is a small, percussion-sensitive explosive located in the base of the case. When the firing pin strikes, the primer detonates and creates a brief flame or shock that travels into the propellant powder. This causes the powder to burn rapidly, generating high-pressure gas that propels the bullet out of the cartridge and down the barrel. The bullet is the projectile, not involved in starting the ignition, and the headstamp is just markings identifying the manufacturer and lot. The powder itself is the propellant that burns to produce the gases once ignition has occurred.